How aquaponics can improve aquaculture and help feed a hungry … · 2018-10-12 · 0DVWHU¶VWKHVLV How aquaponics can improve aquaculture and help feed a hungry world. Iona Flett

Master‘s thesis

How aquaponics can improve aquaculture

and help feed a hungry world.

Iona Flett

Advisor: Rannveig Björnsdóttir

University of Akureyri Faculty of Business and Science

University Centre of the Westfjords Master of Resource Management: Coastal and Marine Management

Ísafjörður, May 2017

Supervisory Committee Advisor: Dr Rannveig Björnsdóttir Reader: Name, title Program Director: Dr Catherine Chambers

Iona Flett How aquaponics can improve aquaculture and help feed a hungry world.

45 ECTS thesis submitted in partial fulfilment of a Master of Resource Management degree in Coastal and Marine Management at the University Centre of the Westfjords, Suðurgata 12, 400 Ísafjörður, Iceland

Degree accredited by the University of Akureyri, Faculty of Business and Science, Borgir, 600 Akureyri, Iceland

Copyright © 2017 Iona Flett All rights reserved Printing: University Centre of the Westfjords and/or Printer, town, Month YEAR

Declaration

I hereby confirm that I am the sole author of this thesis and it is a product of my own

academic research.

__________________________________________

Iona Flett

Abstract

Aquaponics is the practice of combining aquaculture with hydroponics. This methodology not only improves the water quality of aquaculture effluent, but also maximises the use of the resources involved in fish and vegetable production. Aquaponics, and the related model of Integrated Multi-Trophic Aquaculture, are still at relatively early stages of research and development, but they have great potential to improve the way that aquaculture is managed, to increase the value of aquaculture businesses, and to increase the amount of sustainably produced food available for human consumption.

This thesis explores the idea that aquaponics is a viable and important production strategy because its design is based on the interconnectedness of an ecosystem; this is the principle of agroecology, which some say is vital for the future of agriculture.

Part of the project is a case study of an Icelandic aquaculture company, Matorka, whose directors were interested in re-designing their production system to incorporate aquaponics principles and increase the amount and variety of marketable produce. A trial was conducted in collaboration with the company, to grow edible plants using the aquaculture effluent, and scientifically analyse the nutrient content of the water in different parts of the system. The results of the trial may be used by Matorka to help improve the sustainability of their business in the future.

The discussion in this thesis uses the results of the trial and other literature to demonstrate that aquaponics has the potential to improve aquaculture, advance ecosystem-based coastal management and contribute to international sustainable development goals.

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Table of Contents

LIST OF FIGURES ......................................................................................................................................... XI

LIST OF TABLES ........................................................................................................................................ XIII

ACKNOWLEDGEMENTS ............................................................................................................................ XIV

1 INTRODUCTION ............................................................................................................................... 15 1.1 BACKGROUND ....................................................................................................................................... 15 1.2 RESEARCH AIMS ..................................................................................................................................... 17 1.3 ECOSYSTEM BASED MANAGEMENT............................................................................................................ 19 1.4 AGROECOLOGY ...................................................................................................................................... 20 1.5 AQUAPONICS ........................................................................................................................................ 21 1.6 RESEARCH OUTPUTS AND THESIS STRUCTURE ............................................................................................... 22

2 RESEARCH METHODS ....................................................................................................................... 25 2.1 TECHNICAL LITERATURE REVIEW ................................................................................................................ 25

2.1.1 Objectives ................................................................................................................................ 25 2.1.2 Limitations and problems ........................................................................................................ 26

2.2 SURVEY ................................................................................................................................................ 26 2.2.1 Objectives ................................................................................................................................ 26 2.2.2 Survey method ......................................................................................................................... 27 2.2.3 Limitations and problems ........................................................................................................ 28

2.3 MATORKA AQUAPONICS TRIAL .................................................................................................................. 29 2.3.1 Objectives ................................................................................................................................ 29 2.3.2 Experimental and analytical methods ..................................................................................... 31 2.3.3 Limitations and problems ........................................................................................................ 47

2.4 SWOT ANALYSIS.................................................................................................................................... 49 2.4.1 Objectives ................................................................................................................................ 49 2.4.2 Method .................................................................................................................................... 49 2.4.3 Limitations and problems ........................................................................................................ 49

3 RESULTS ........................................................................................................................................... 51 3.1 TECHNICAL LITERATURE REVIEW ................................................................................................................ 51

3.1.1 The theoretical system ............................................................................................................. 51 3.1.2 Types of systems ...................................................................................................................... 52 3.1.3 Hydroponics techniques ........................................................................................................... 55 3.1.4 Water chemistry ...................................................................................................................... 57 3.1.5 Filtration .................................................................................................................................. 61 3.1.6 Fish ........................................................................................................................................... 61 3.1.7 Fish feed ................................................................................................................................... 63 3.1.8 Food safety .............................................................................................................................. 64 3.1.9 Plants ....................................................................................................................................... 66 3.1.10 Pests .................................................................................................................................... 70 3.1.11 Energy ................................................................................................................................. 71 3.1.12 Technology .......................................................................................................................... 73 3.1.13 Advice, guidance, and the internet ..................................................................................... 74

3.2 SURVEY RESULTS .................................................................................................................................... 75 3.3 MATORKA AQUAPONICS TRIAL RESULTS ...................................................................................................... 80

3.3.1 Plant growth characteristics .................................................................................................... 80 3.3.2 Nutrient and water analysis .................................................................................................... 85 3.3.3 Microalgae growth .................................................................................................................. 92

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4 DISCUSSION AND CONCLUSIONS ...................................................................................................... 95 4.1 DISCUSSION OF MATORKA RESULTS ............................................................................................................ 95

4.1.1 Characterising the Matorka effluent ........................................................................................ 95 4.1.2 Growth under different conditions ........................................................................................... 96 4.1.3 Efficacy of nutrient removal ................................................................................................... 100 4.1.4 Developing aquaponics at a commercial scale in southern Iceland ....................................... 102

4.2 AQUAPONICS STRENGTHS AND OPPORTUNITIES ........................................................................................... 107 4.2.1 Resource efficiency ................................................................................................................. 108 4.2.2 Making money ........................................................................................................................ 109 4.2.3 Industrial food production has issues ..................................................................................... 111 4.2.4 Consumer choice .................................................................................................................... 112 4.2.5 Aquaponics for everyone ........................................................................................................ 112

4.3 WEAKNESSES AND THREATS .................................................................................................................... 116 4.3.1 Know-how .............................................................................................................................. 117 4.3.2 Time and effort ....................................................................................................................... 117 4.3.3 Costs and risks ........................................................................................................................ 118 4.3.4 Regulation .............................................................................................................................. 118 4.3.5 Unscrupulous salesmen .......................................................................................................... 119

4.4 AQUAPONICS AS AGROECOLOGY .............................................................................................................. 121 4.4.1 Fish ......................................................................................................................................... 124 4.4.2 Plants ...................................................................................................................................... 126 4.4.3 Nutrient and energy flows ...................................................................................................... 126 4.4.4 External elements ................................................................................................................... 127

4.5 IMPROVING AQUACULTURE ..................................................................................................................... 129 4.6 SUSTAINABLE DEVELOPMENT ................................................................................................................... 131 4.7 STRATEGIC PLANNING ............................................................................................................................ 134

4.7.1 Strategies ............................................................................................................................... 138

5 RESEARCH SUMMARY .................................................................................................................... 141 5.1 MAIN FINDINGS .................................................................................................................................... 141 5.2 POTENTIAL IMPACTS .............................................................................................................................. 144 5.3 LIMITATIONS AND WEAKNESSES ............................................................................................................... 145 5.4 FURTHER RESEARCH .............................................................................................................................. 145

6 REFERENCES ................................................................................................................................... 147

7 APPENDICES ................................................................................................................................... 157 APPENDIX A – SURVEY DETAILS ......................................................................................................................... 157 APPENDIX B – SURVEY RESPONSES ..................................................................................................................... 159 APPENDIX C – COMPLETE EXPERIMENT RESULTS ................................................................................................... 164 APPENDIX D – 2030 SUSTAINABLE DEVELOPMENT GOALS RELATING TO FOOD, AGRICULTURE, COASTS AND OCEANS. ......... 174 APPENDIX E – POSTER FOR GEORG MEETING, 2012 ........................................................................................... 179

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List of Figures

FIGURE 1. AN AQUAPONICS SYSTEM REPRESENTED AS AN AGROECOSYSTEM. .................................................................... 21

FIGURE 2. EXPERIMENTAL SET-UP. ........................................................................................................................... 31

FIGURE 3. SCHEMATIC OF THE MATORKA FACILITY SHOWING WATER FLOWS, NUTRIENT SOURCES, AND SAMPLING LOCATIONS. .. 32

FIGURE 4. BIOFILTER VIEWED FROM ABOVE, WITH FOUR CHAMBERS CONTAINING PUMICE. ................................................. 33

FIGURE 5. BELL SIPHONS BUILT FOR EACH EXPERIMENT BOX (FROM SOMERVILLE, ET AL., 2014; THEIR FIGURE 4.58). ............. 35

FIGURE 6. EXPERIMENT BOXES DURING SET-UP AND EQUILIBRATION. .............................................................................. 35

FIGURE 7. ROCKET AND LETTUCE SEEDLINGS GROWING IN COCONUT COIR GERMINATION PADS PRIOR TO TRANSPLANTING INTO THE

EXPERIMENT BOXES. .................................................................................................................................... 36

FIGURE 8. TEN INDIVIDUALS OF EACH SPECIES WERE ANALYSED AT DAY 0 TO PROVIDE A BASELINE. ....................................... 38

FIGURE 9. EXAMPLE OF DRY WEIGHTS OF LEAVES, STEMS AND ROOTS BEING DETERMINED................................................... 39

FIGURE 10. MICROALGAE TUBS PICTURED DURING THE EXPERIMENT. ............................................................................. 40

FIGURE 11.EXAMPLE OF ALGAL FILTRATE SAMPLES AFTER FILTERING AND DRYING. ............................................................. 42

FIGURE 12. FIALAB SPECTROMETER EQUIPMENT AT MATÍS, REYKJAVIK........................................................................... 43

FIGURE 13. THE DIFFERENT ELEMENTS OF AQUAPONICS THAT SOMEONE PLANNING AN AQUAPONICS SET-UP SHOULD CONSIDER. 52

FIGURE 14. EXAMPLE OF THE PHOTO SERIES FOR EACH EXPERIMENT BOX TO MONITOR PLANT GROWTH DURING THE EXPERIMENT.

............................................................................................................................................................... 80

FIGURE 15. HYDROTON AND PUMICE EXPERIMENT BOXES SHOWING THE DEVELOPMENT OF ALGAL MATS IN THE GROWTH MEDIA.

............................................................................................................................................................... 81

FIGURE 16. PERCENTAGE CHANGE IN TOTAL PLANT LENGTH FOR THE DIFFERENT PLANT TYPES AND EXPERIMENTAL TREATMENTS.

............................................................................................................................................................... 83

FIGURE 17. PERCENTAGE CHANGE IN THE TOTAL LEAF AREA MEASUREMENTS FROM THE START TO THE END OF THE EXPERIMENT,

SHOWN FOR THE 12 DIFFERENT TREATMENTS (COLUMNS) AND THE THREE DIFFERENT PLANT TYPES (SERIES). ................ 84

FIGURE 18. PERCENTAGE CHANGE IN THE TOTAL DRY MASS MEASUREMENTS FROM THE START TO THE END OF THE EXPERIMENT,

SHOWN FOR THE 12 DIFFERENT TREATMENTS (COLUMNS) AND THE THREE DIFFERENT PLANT TYPES (SERIES). ................ 84

FIGURE 19. DATA FOR ALL THREE OF TOTAL LEAF AREA, TOTAL DRY MASS, AND PLANT LENGTH COMBINED TO SHOW

DIFFERENCES BETWEEN MEDIA TYPES. ............................................................................................................. 85

FIGURE 22. NITRITE RESULTS FOR WEEKLY WATER TESTS FROM THE THREE 'BIOFILTERED' AND THREE 'UNFILTERED' BOXES.

TREATMENTS: UNFILTERED, HYDROTON (UH); UNFILTERED, PUMICE (UP); UNFILTERED, RAFT (UR); BIOFILTERED,

HYDROTON (BR); BIOFILTERED, PUMICE (BP); BIOFILTERED, RAFT (BR). ............................................................... 89

FIGURE 21. NITRATE RESULTS FOR WEEKLY WATER TESTS FROM THE THREE 'TAP WATER' AND THREE 'NUTRIENT CONTROL' BOXES.

TREATMENTS: TAP WATER, HYDROTON (TP); TAP WATER, PUMICE (TP); TAP WATER, RAFT (TR); NUTRIENT, HYDROTON

(NH); NUTRIENT, PUMICE (NP); NUTRIENT, RAFT (NR). .................................................................................... 89

FIGURE 20. NITRATE RESULTS FOR WEEKLY WATER TESTS FROM THE THREE 'BIOFILTERED' AND THREE 'UNFILTERED' BOXES.



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FIGURE 25. PHOSPHATE RESULTS FOR WEEKLY WATER TESTS FROM THE THREE 'TAP WATER' AND THREE 'NUTRIENT CONTROL'

BOXES. TREATMENTS: TAP WATER, HYDROTON (TP); TAP WATER, PUMICE (TP); TAP WATER, RAFT (TR); NUTRIENT,

HYDROTON (NH); NUTRIENT, PUMICE (NP); NUTRIENT, RAFT (NR). .................................................................... 90

FIGURE 24. PHOSPHATE RESULTS FOR WEEKLY WATER TESTS FROM THE THREE 'BIOFILTERED' AND THREE 'UNFILTERED BOXES.



FIGURE 23. NITRITE RESULTS FOR WEEKLY WATER TESTS FROM THE THREE 'TAP WATER' AND THREE 'NUTRIENT CONTROL' BOXES.

TREATMENTS: TAP WATER, HYDROTON (TP); TAP WATER, PUMICE (TP); TAP WATER, RAFT (TR); NUTRIENT, HYDROTON

(NH); NUTRIENT, PUMICE (NP); NUTRIENT, RAFT (NR). .................................................................................... 90

FIGURE 27. TOTAL AMMONIA NITROGEN RESULTS FOR WEEKLY WATER TESTS FROM THE 'TAP WATER' AND 'NUTRIENT CONTROL'

BOXES. TREATMENTS: TAP WATER, HYDROTON (TP); TAP WATER, PUMICE (TP); TAP WATER, RAFT (TR); NUTRIENT,

HYDROTON (NH); NUTRIENT, PUMICE (NP); NUTRIENT, RAFT (NR). .................................................................... 91

FIGURE 26. TOTAL AMMONIA NITROGEN RESULTS FOR WEEKLY WATER TESTS FROM THE 'BIOFILTERED' AND 'UNFILTERED' BOXES.



FIGURE 28. MICROALGAE CONCENTRATIONS IN THE FOUR DIFFERENT EXPERIMENT BOXES OVER 28 DAYS. .............................. 93

FIGURE 29. OPTICAL DENSITIES OF THE ALGAL CULTURES OVER TIME, MEASURED AT 640 NM. ............................................. 93

FIGURE 30. ABSORBANCE AT 640 NM PLOTTED AGAINST THE BIOMASS (G/L) OF SAMPLES FROM EACH ALGAL TREATMENT........ 94

FIGURE 31. PART OF THE MATORKA FACILITY AT FELLSMULI, ON THE BANK OF THE MINNIVALLALAEKUR RIVER. SOME OF THE

OUTDOOR ARCTIC CHAR TANKS CAN BE SEEN, AND THE SIDE OF THE BUILDING HOUSING THE EXPERIMENT. .................. 103

FIGURE 32. SIGN INSTALLED BY A REGIONAL NATURAL RESOURCE MANAGEMENT ORGANISATION INFORMING ABOUT THE IMPACT

OF TILAPIA IN QUEENSLAND, AUSTRALIA (SUPPLIED: MATT MOORE, CATCHMENT SOLUTIONS). THE FINE FOR POSSESSING A

TILAPIA (DEAD OR ALIVE) IS AU$20 000 (WATSON, 2016). ............................................................................. 124

FIGURE 33. FIVE WAYS AQUAPONICS CAN IMPROVE AQUACULTURE .............................................................................. 130

FIGURE 34. HOW AQUAPONICS CAN HELP WITH SUSTAINABLE DEVELOPMENT. ................................................................ 132

FIGURE 35. INSPIRATIONAL CONCEPTUAL MODELS, SOIL TO SKY OF AGROECOLOGY VS INDUSTRIAL AGRICULTURE , THE FUTURE

OF FOOD AND AGRICULTURE. THE GLOBAL TRENDS AND CHALLENGES THAT ARE SHAPING OUR FUTURE , AND SEVEN LIFE

LEARNINGS FROM SEVEN YEARS OF READING, WRITING AND LIVING. REFERENCES WITHIN TEXT. ............................... 133

FIGURE 36. THE REDUSE METHODOLOGY DESCRIBED IN THE UNEP S 2016 FRAMEWORK ON SHAPING SUSTAINABLE LIFESTYLES

(THEIR FIGURE 6, P29). .............................................................................................................................. 137

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List of Tables

TABLE 1. LABELS AND DETAILS OF EXPERIMENT VARIABLES. ........................................................................................... 37

TABLE 2. NITRATE AND NITRITE GUIDELINES FOR SOME AQUACULTURE SPECIES (FROM HEATH, ET AL., 2010). THE TABLE SHOWS

TOLERANCE LIMITS FOR SOME SPECIES TESTED IN NEW ZEALAND. ......................................................................... 59

TABLE 3. OPTIMAL WATER QUALITY PARAMETERS FOR THE DIFFERENT PARTS OF AN AQUAPONICS SYSTEM (SOMERVILLE ET AL.,

2014) ...................................................................................................................................................... 60

TABLE 4. FISH AND INVERTEBRATE CANDIDATES FOR FRESHWATER INTEGRATED MULTITROPHIC AQUACULTURE OPERATIONS IN

TROPICAL AND TEMPERATE REGIONS (AFTER BAKHSH ET AL, 2014). ...................................................................... 62

TABLE 5. PLANT CANDIDATES FOR FIMTA OPERATIONS IN TEMPERATE TO COLD REGIONS (TABLE 3 IN BAKHSH ET AL, 2014). .. 66

TABLE 6. RESPONSES TO QUESTION 1 OF THE COMMUNITY SURVEY - COMMUNITY PARTICIPATION. ...................................... 75

TABLE 7. RESPONSES TO QUESTION 4 OF THE COMMUNITY SURVEY - GARDEN DETAILS. ...................................................... 76

TABLE 8. RESPONSES TO QUESTION 9 OF THE COMMUNITY SURVEY - AQUAPONICS IN A WORLD CONTEXT. ............................. 76

TABLE 9. RESPONSES TO QUESTION 7 OF THE COMMUNITY SURVEY - POSITIVE ASPECTS OF AQUAPONICS. .............................. 77

TABLE 10. RESPONSES TO QUESTION 8 OF THE COMMUNITY SURVEY - NEGATIVE ASPECTS OF AQUAPONICS. .......................... 78

TABLE 11. P-VALUES FOR PAIRED T-TESTS PERFORMED ON EXPERIMENTAL DATA. AN ASTERISK INDICATES SIGNIFICANCE. .......... 82

TABLE 12. RESULTS OF WEEKLY WATER QUALITY MEASUREMENTS ON WATER FROM VARIOUS LOCATIONS AROUND MATORKA. .. 86

TABLE 13. RESULTS OF REGRESSION ANALYSIS ON EACH SET OF WEEKLY SAMPLES. ............................................................. 88

TABLE 14. DETAILS OF THE AGROECOLOGY MODEL FOR DIFFERENT TYPES OF AQUAPONICS SYSTEMS, INCLUDING A PROPOSED

MATORKA UPGRADE INCLUDING A CUSTOM-DESIGNED AQUAPONICS SYSTEM. ....................................................... 122

TABLE 15. AGROECOLOGICAL PRINCIPLES FOR THE DESIGN OF BIODIVERSE, ENERGY EFFICIENT, RESOURCE-CONSERVING AND

RESILIENT FARMING SYSTEM. (FROM ALTIERI ET AL, 2012). .............................................................................. 127

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Acknowledgements

Thank you to all the people who generously helped with this research, especially Sveinbjörn

Oddsson and the other staff at Matorka and Matís - Gummi, Thorunn, Thoridur, Gisli and

Jon who provided lots of practical assistance, advice and friendly chats; My academic guides

– Rannveig Björnsdóttir, Ragnar Jóhannsson, Sjöfn Sigurgísladóttir, Stefania Karlsdóttir and

also the above-mentioned Sveinbjörn, who read, discussed, advised and showed enthusiasm

despite their very busy schedules; My Ísafjörður companions - Arnthor, Clasina, Theresa,

Graham and the other UCW students for moral support and R&R; and my ‘Reykjavik

family’ - Sjöfn, Stefan, Snori and Tina who welcomed me into their lovely home and inspired

me with their jet-setting lifestyle!

My biggest thanks are for my family, John, Jackie, Sorcha and Morven Flett, and the newest

and best member, Phil Hrstich, for encouragement, financial support, and for the mysterious

belief they have always had in me. Sorry it took so long, everyone!

I would also like to acknowledge the participation of the 47 people who filled in my survey

form after seeing it advertised on one of the following aquaponics forums:

http://community.theaquaponicsource.com/forum

http://www.aquaponics.net.au/forum

http://www.backyardaquaponics.com/forum

http://apps.1aquaponics.com.au/Forum

http://www.permies.com/t/22386/aquaponics

http://www.aquaponicshq.com/forums/forum.php

http://www.aquaculturehub.org/group/aquaponics








15

1 Introduction

1.1 Background

Wild fish stocks are at an all-time low, with many species on the brink of an irreversible

decline (Rosenblum, et al., 2012). Overfishing is on every list of coming or current

environmental disasters (Black, 2012) but with an ever-expanding human population, the

pressure on fish to play a significant role in food and nutrition security can be expected to

grow (Duarte, et al., 2009; FAO, 2016).

The “Sea Around Us” database shows that wild fish catches peaked in 1996 and have been

falling by 1.22 million tonnes (~1%) per year since (Golden, 2016). Further reductions are

expected due to degraded ecosystems, continued coastal development, destructive fishing

practices and climate change. Serious human health impacts are predicted to develop from

fishery declines, because 1.39 billion people worldwide currently get more than 20% of their

essential micronutrients from fish. Poor people, especially in the tropics, will be more at risk

(Golden, 2016).

Aquaculture appears to be a viable alternative to wild fishing, with the potential to reduce

the pressure on some capture fisheries, and in 2014, for the first time, world aquaculture

produced more fish for human consumption than fishing did (FAO, 2016). However, there

are many environmental concerns with conventional aquaculture too, particularly in the

intensive form favoured by large companies (Walsh, 2011).

Fork at Fellsmuli, October 2012 (I. Flett)

An emerging paradigm (in aquaculture as well as in other fields of natural resource

management) is for planning and management to have a focus on whole ecosystems, rather

than solely on anthropogenic requirements. In the literature, this has been referred to as an

‘ecosystem approach’ to aquaculture. In practical terms, ecologically sensitive aquaculture

projects ensure food production but reduce or eliminate the detrimental environmental

impacts that have been observed in conventional aquaculture (Yusoff, 2003).

A workshop of experts convened by the FAO in Spain in 2007 agreed that: “An ecosystem

approach for aquaculture (EAA) is a strategy for the integration of the activity within the

wider ecosystem in such a way that it promotes sustainable development, equity, and

resilience of interlinked social and ecological systems” (Soto, et al., 2008).

In addition, the publication resulting from the workshop states that: “Such strategy should

be guided by three main principles that should ensure the contribution of aquaculture to

sustainable development: i) aquaculture should be developed in the context of ecosystem

functions and services with no degradation of these beyond their resilience capacity; ii)

aquaculture should improve human wellbeing and equity for all relevant stakeholders; and

iii) aquaculture should be developed in the context of (and integrated to) other relevant

sectors” (Soto, et al., 2008).

In other words, the three linked spheres of sustainable development - environmental, social,

and economic, are upheld and reinforced by this type of aquaculture.

Based on this definition, the ultimate example of EAA could be aquaponics, and yet

aquaponics has taken a long time to become established, and is still underutilised considering

its great potential for improving aquaculture in line with the three principles listed above.

Aquaponics is defined as the polyculture of fish and plants. The word derives from a

combination of aquaculture and hydroponics, which is the practice of growing plants without

soil. Typically, aquaponics is part of a recirculated aquaculture system (RAS) where fish

waste is used as fertiliser for the plants, to the benefit of both the product streams (Pantanella,

2008). Usually, water is the growing medium for the plants, with fish living in that water,

but there are many possible varieties of systems. Other designs use soil, gravel or biological

material for the plant growth media, and the used fish water may be pumped over the plants,

filtered first, and/or chemically adjusted before being used for irrigation.

17

Jones (2002) notes that aquaponics is a cycle that is naturally present in all waterways, where

plants grow using the waste from fish as nutrients, and fish benefit from the cleaner,

oxygenated water. In a natural ecosystem, the fish could be eating plants, including

microscopic algae, and they might be eating insects, which would in turn be eating down the

food chain – subsisting on phytoplankton or zooplankton. Other elements of this natural food

web replicated in an aquaponics facility could include crustaceans such as shrimp or crabs,

or even higher animals such as ducks or geese, which, in the case of the Incas of Peru, were

utilised to move nutrients from the water, where they ate aquatic plants and small fish, to the

land, where they roosted and fertilised the soil (Jones, 2002).

The concept of aquaponics systems as self-contained ecosystems lends itself to the field of

agroecology, and so it is through this lens that that the arguments in the discussion will be

made.

1.2 Research aims

The aims of this research project were:

1) To review the current aquaponics literature and describe the status of the scientific and

technological knowledge in the aquaponics industry, as well as discussing examples of

successful business models.

This report was originally intended to be useful as background knowledge to the Icelandic

arm of the Aquaponics NOMA research project which ran from 2012 to 2015 (Skar, et al.,

2015). Aquaponics NOMA was funded by the Nordic Innovation Council, and aimed to

establish an aquaponics business cluster in the Nordic region in order to support a more

competitive and sustainable marine and food sector. The Icelandic partners, Matís Ltd. (the

Icelandic food and biotech research organisation) and Matorka ehf (an Icelandic aquaculture

company) were happy to have a Master’s student participating, and suggested that a desktop

analysis would be useful. This section of the thesis is framed around the following two

objectives of the Aquaponics NOMA project:

• To increase the scientific and practical knowledge base when applying ecosystem

approaches in aquaculture and horticulture combined.

• To investigate suitable fish and crop species for Nordic aquaponics in terms of

growth, quality, effluents, temperature, and nutrient balance1.

Unfortunately, the gap between beginning and submitting this thesis has been four years,

and Aquaponics NOMA has finished (Skar, et al., 2015), while Matorka have drawn their

own conclusions about the usefulness of aquaponics. The literature review has been updated

and now reflects the state of the industry in 2017.

2) To conduct a small-scale aquaponics trial utilising the above literature analysis to

determine which methods would be most suitable if Matorka is to expand their business and

build a profitable aquaponics facility. Given that Matorka might not be interested in the

results any more, other real or theoretical aquaculture companies will be considered.

3) To explore the potential of aquaponics to contribute to the growing problem of how to

provide enough food and nutrition for Earth’s >7.4 billion inhabitants (Worldometers, 2017),

while prioritising the protection of the habitat in which these people must live. Clearly, the

issue of food and nutrition security is not going to be solved by one method alone, but by a

variety of changes (some local, some global) to the way we capture, produce, grow, process,

package, distribute and market food. It is the underlying assumption of this research project

that any innovative solutions must accord with the principles of modern ecosystem-based

natural resource management, which has grown out of the same ethos as ‘sustainable

development’: "Development that meets the needs of the present without compromising the

ability of future generations to meet their own needs" (Bruntland Commission; World

Commission on Environment and Development, 1987).

1 Other Aquaponics NOMA objectives, which have not been specifically addressed in this thesis, were:

• To further optimise management practices and technologies in aquaponics, e.g. treatment of

waste water and solid wastes to protect the environment from pollution and pathogens;

• To design commercially viable aquaponic production models for the Nordic region and

investigate consumer market potentials including the possibility for eco-labelling; and to

• Secure efficient dissemination and knowledge transfer necessary for a viable scientific and

practical Nordic cluster formation in aquaponics.

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1.3 Ecosystem Based Management

Ecosystem Based Management (EBM) is an integrated approach to resource management

which seeks to consider all the related elements of the ecosystem that the resource is affected

by, including human elements. EBM works across sectors and with multiple stakeholders,

with management aiming to be adaptive, flexible, and responsive (NOAA, n.d.). There are

tens of thousands of articles that describe the application of EBM, so unsurprisingly, there

are multiple definitions and uncertainty surrounding exactly what EBM is in different fields

of resource management (Dolan, et al., 2015). EBM in coastal and marine management is

often said to be place-based and regional in scope, so that ecosystem-based fisheries or

aquaculture management takes a system-level perspective rather than trying to manage a

single species in isolation (Dolan, et al., 2015).

Norse (2010) makes the point that despite regional, systems-level, multi-stakeholder EBM

being the aim in marine management, there are multiple examples of where governance is

fragmented, complex trophic interactions are not understood until it is too late, and

management has not gone well (e.g. 80% of fisheries are fully exploited or overexploited;

FAO, 2009; Norse, 2010; Worm, et al., 2009).

Nevertheless, EBM is a paradigm that can work, especially when effective marine spatial

planning is incorporated, and biodiversity conservation goals are part of the equation (i.e.

the management is not purely focused on human economic outcomes; Norse, 2010; NOAA,

n.d.; Worm, et al, 2009).

To develop the sustainable aquaculture industry by incorporating aquaponics and IMTA

principles, as proposed in this thesis, it is essential that best practice EBM (and/or the

Ecosystem-Approach; Soto, et al, 2008) is the foundation. This means (on the human side)

that issues of international, inter-generational and inter-sector equity are addressed by

management plans, and all management frameworks or proposals for change would need to

be consultative, collaborative and evidence based. This thesis reviews some of that

foundational evidence.

1.4 Agroecology

Agroecology is an academic framework that has been defined as “the application of

ecological concepts and principles to the design and management of sustainable

agroecosystems” (Gliessman, 2004). Ecological knowledge has always informally guided

food gathering and growing systems, and so arguably, modern agricultural technology has

ecological roots. However, agriculture has become so thoroughly industrialised and

commercialised in modern Western societies (and is therefore far from its traditional

ecological history), that the concept of agroecology has emerged as a backlash against

industrial agriculture. Agroecology has been used over the last ~25 years to understand and

study agricultural systems (Bland & Bell, 2007), to explore the ways that natural ecosystem

structures and functions can improve the environmental, social and economic sustainability

of agriculture (Gliessman, 2004), and also to discuss the scientific basis for an ‘alternative’

agriculture (Altieri, 1995).

The United Nations Special Rapporteur on the Right to Food from 2008 to 2014 advocated

for the use of an agroecological approach to food insecurity and food sovereignty issues

(Mendez, et al., 2013; Schutter, 2014), and this theme was echoed in another UN Special

Rapporteur report issued this year on the damage that pesticides cause to human health,

human rights and the ecosystems (United Nations Human Rights Council, 2017).

Gliessman (2004) explains that an agroecosystem is created by humans who alter a natural

ecosystem to establish agricultural production. This involves changing the structure and

function of the natural ecosystem in several important ways, especially in terms of the energy

flows, the nutrient cycling, the population regulation mechanisms that are employed

(including the diversity of ‘pest’ species), and importantly, the dynamism of the ecosystem.

These four aspects of ecosystem function are used in agroecology to study agroecosystems,

and also to convert unsustainable and conventional agroecosystems into sustainable ones.

Figure 1 presents a conceptual model of an agricultural activity interacting with its

surroundings. The elements of this diagram are discussed further in Chapter 4.4.

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Figure 1. An aquaponics system represented as an agroecosystem. The agroecosystem is the unit represented by the dashed line (After Gleissman, 1998). Orange squares within the agroecosystem are living elements and the products made from them; black arrows are energy and nutrient flows; large green and red arrows represent inputs and outputs that are external to the agroecosystem; see text for further explanation.

1.5 Aquaponics

Aquaponics is discussed in this paper as if it is an industry. It might be more accurate by

economic definitions to call it a cottage industry (Investor_Glossary, 2017) or a branch of

another industry (such as farming or gardening) since there are relatively few aquaponics

jobs, and aquaponics presumably has a very low economic impact everywhere that it is

practiced. However, aquaponics does have businesses, associations, training courses,

conferences, books, trade journals and extremely devoted advocates concerned solely with

its activities and its development. In terms of the language and culture of aquaponics, it

seems to fit somewhere between gardening, farming and sustainable living, and has

borrowed terminology, techniques, and expertise from all of these fields as well as

hydroponics and aquaculture.

‘The aquaponics community’ is loosely defined for the purposes of this paper, as everyone

with an interest in aquaponics, whether they are a ‘backyard’ community-based aquaponic

gardener, an ‘industry leader’ type, who may be running an aquaponics business and be a

source of advice and mentoring, or one of the few academics involved in attempting to

formalise aquaponic science. As in any community, there are conflicts, politics, and

arguments. In the case of the aquaponics community, one of the arguments is about what can

be called aquaponics and what should not.

Some purists have a strict definition of the term, which excludes systems that are not

recirculating, not ‘organic’, involve soil or nutrient addition and/or do not use fresh water.

For the purposes of this research, a much broader definition is used, so that techniques from

sustainable aquaculture, biological water treatment, and IMTA can be considered, depending

on the site-specific requirements of the system. Aquaponics for this thesis, therefore, refers

to any system growing plants (including algae) and fish (including shellfish and crustaceans)

together.

1.6 Research outputs and thesis structure

This research project has been conducted in three parts. Firstly, extensive online research

was undertaken to collect technical information on aquaponics. An important second

element was a set of experiments which obtained quantitative data about the feasibility of

adding a hydroponics arm to the production system at Matorka. Finally, analysis of the

Matorka data and other literature informs an analysis of aquaponics in a global context.

This introductory chapter has set the scene and defined the important terms and themes used

throughout the rest of the paper.

Chapter 2 details the research methods that were used, including mention of their limitations

and problems where applicable.

The following research outputs are presented in Chapters 3 and 4:

3.1 and 3.2 Technical Literature Review and Community Survey. How is aquaponics

practiced at different scales? What technical aspects does a company need to consider

before building an aquaponics facility?

23

3.2 and 4.1 Report on Matorka Aquaponics Trial. Quantitative data were collected and

analysed during a trial at Matorka’s existing fish farm in 2012, and the report on this

part of the research was intended to be a contribution to Matorka’s business

development, and to the aquaponics literature.

4.2 and 4.3 SWOT analysis of the Aquaponics Industry. What are the strengths,

weaknesses, opportunities, and threats currently observed in the aquaponics industry?

From these, four sections are developed as further research discussions:

4.4 Aquaponics as Agroecology. In terms of agroecology, and the ecological approach

to aquaculture, how can the various internal and external elements of aquaponics be

defined and understood? How is this approach useful for analysing the role and

potential of a fledgling industry?

4.5 Improving Aquaculture. Aquaponics has the potential to improve the sustainability

of conventional aquaculture, in economic, social, and particularly in ecological terms.

4.6 Sustainable Development. It is important that aquaculture problems are resolved

in order for nations to meet international sustainable development goals. Investment

in sustainable aquaculture, broader understanding of aquaponics techniques, and

policies that encourage agroecology would help the world move towards these goals.

4.7 Strategic Planning. What strategic direction should aquaponics industry leaders

propose to enable its expansion in both developed and developing countries, given that

aquaponics at different scales may be an important tool for coastal ecosystem-based

management and for international sustainable development goals, especially related to

improving global food and nutrition security in the future?

Chapter 5 summarises the main findings and potential impacts of the research, and suggests

where further research could expand on the results of this thesis.

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2 Research Methods

2.1 Technical literature review

2.1.1 Objectives

The literature review is intended to be a thorough examination of the state of the published

knowledge about aquaponics. As well as published academic sources, grey literature has

been consulted, since there is a wealth of information self-published online on reputable

websites, and in newsletters and fact sheets.

The objective of the literature review is to summarise the state of knowledge about

aquaponics techniques, including the history of aquaponics, specific information about types

of systems, the science behind the process, suitable cultivars, and technical specifications of

equipment. The literature review incorporates papers published up to 2017. Most of the

literature review was conducted before the design of the Matorka trial, so it was intended to

be background to those experiments as well as a potential contribution to the Aquaponics

NOMA research project.

When I started this project in 2012, there was little research being done about aquaponics in

universities, which meant there was a dearth of peer-reviewed literature. However, a Google

Scholar search for aquaponics articles published between 2013 and 2017 yields 1750 papers

and web-stored theses. Over the same period of time, Integrated Multi-Trophic Aquaculture

Hekla and the moon, October 2012 (I. Flett)

produced 5490 publications, perhaps reflecting the fact that aquaculture scientists tend to

use IMTA terminology rather than aquaponics, even although there is extensive crossover

in techniques and technology. I have focused on the most relevant articles from both

aquaponics and IMTA.

2.1.2 Limitations and problems

Because of the non-academic nature of much aquaponics research, some of the sources

considered for the literature review had not been peer reviewed, and were not all written in

an impartial and objective scientific style. This could mean that there are inaccuracies

because the articles have had only a cursory fact check, or because the author is presenting

an opinion. There could be deliberate or accidental misinformation published since it is

sometimes difficult to know the purpose for which the author has written the piece (for

example they might benefit from the sales of aquaponics equipment that they are discussing

in the article). To avoid the problem of trusting an untrustworthy source, or believing

misinformation, an effort has been made to examine the backgrounds of authors where

possible, and to critically consider the language used and the author’s reported credentials.

If there was any doubt about the veracity of the information, the article was simply not

discussed in this thesis, but where useful information is included from an uncertain source,

it is mentioned in the review.

2.2 Survey

2.2.1 Objectives

The vast majority of people interested in aquaponics are not farmers, aquaculturalists, or

coastal managers, despite the theoretical advantages aquaponics could have for these groups.

Instead, aquaponics is mostly practiced by ‘backyard’ enthusiasts (Love, et al., 2014). There

are thousands of people in the US, Canada, Australia and Europe who are fascinated by the

promise of living more sustainably, more self-sufficiently and in closer proximity to their

food production. Aquaponics seems to have fantastic advantages over the current industrial

food production system for those who are willing to invest.

Several universities and colleges have aquaponics facilities and conduct research (e.g.

University of the Virgin Islands, the University of Hawaii, Bangladesh Agricultural

27

University, the University Wisconsin which hosts the Nelson and Pade aquaponics course,

North Carolina State University, The Freshwater Institute in West Virginia, California State

Polytechnic University), and aquaponics is also very popular in North America as a teaching

aid in secondary schools. Still, compared to other types of science, a proportion of the

industry’s development is conducted by non-academic trial and error research, which is quite

extensively discussed on blogs, forums and YouTube videos.

In other words, small-scale experimental practitioners may have ideas and knowledge that

are not available through formal published science. This reality is also the case in other fields

(such as fishing technology, and even pharmaceutical development), and is acknowledged

in the inclusive approach taken in agroecological research, which “emphasises the societal

and knowledge gains from dialogue between researchers, farmers and indigenous

communities. Indigenous knowledge systems and traditional farming practices often yield

site-specific insights that would otherwise be outside the purview of formal science” (PAN,

2009). In the case of aquaponics, traditional farming practices above could refer to the

family-scale community-based aquaponics practiced by non-professionals.

Therefore, a short survey was designed to look at the characteristics of the aquaponics

community. How do they meet, interact, and transfer knowledge? What information does

this community have about aquaponics that could complement the published ‘academic’

knowledge? And since small-scale farmers make up the majority of the industry, how do

they see their industry progressing and changing in the future?

2.2.2 Survey method

The aquaponics community survey was designed to investigate the participation of the

community members, and to confirm some of the ideas that were formed through reading

online aquaponics sources. Another purpose was to seek the opinions of community-based

aquaponics gardeners about the positive, negative, and possible future aspects of aquaponics.

The survey answers provide a snapshot of a limited number of respondents, it is not a

representative sample. Therefore, data collected by the survey cannot be extrapolated to

represent the opinions or characteristics of the whole aquaponics community.

The survey was designed and distributed using the online tool, Survey Monkey (Survey

Monkey, 2017), which allows 10 questions in its free mode. Appendix A shows the survey

questions.

For discussing community contributions, the most recent APA protocols for electronic

sources have been followed (Lee, 2013), except survey responses are treated anonymously

since responders’ names were not requested and therefore anonymity was assumed.

Several active forums were selected on which to advertise the survey:









There are several limitations regarding the survey. Firstly, as stated above, the survey was

not intended to give representative data about the whole aquaponics community, although

since 2013, the results of an international survey have been published giving more

comprehensive data about aquaponics demographics (Love, et al., 2014; Love, et al., 2015).

The questions were aimed at forum participants, to get an idea what that sector is like, but it

is acknowledged that not all forum participants would be interested in completing a survey

(hence there were only 47 respondents in total). Furthermore, there may be a demographic

that is particularly likely to be involved in forums, and of those who are involved, perhaps a

certain type of person is more likely to respond to surveys. The survey responses, therefore,

have more value as background quantitative data than as combined qualitative data.








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2.3 Matorka aquaponics trial

2.3.1 Objectives

Matorka is a successful aquaculture company, founded in 2009, and currently producing

approximately 50 tonnes of Arctic Char per year (Wright, 2016).

The Matorka aquaculture system is not a fully recirculating system (RAS), due to the high

volume and high quality of fresh water available in southern Iceland, where the company

operates. An estimated sixty to seventy percent of the water at the end of the system has been

used more than once as it travels through the system, but it then goes through a solids settling

process and is released into the environment. For this reason, many of the aquaponics system

designs that are discussed by other authors are not completely relevant. For example, much

of the community aquaponics advice and design specifics concentrate on making sure the

filtration system is working correctly so that the health of the fish is not compromised. In

the Matorka system, there is no such requirement that the water be very clean or oxygenated

after the plants have used it, since (at least under the current operating conditions) the fish

are not going to be exposed to that water.

The design of the first Matorka aquaponics trial, and experiments conducted during this early

stage of research, were focused on a number of issues:

• Treating the wastewater so that there are lower nutrient levels in the water that is

released back into the environment. The cost of this effluent treatment, should it be

employed at a larger scale, could theoretically be subsidised by the sale of the

vegetable crops, and Matorka would also benefit by being the first commercial

aquaculture company in Iceland to treat their waste water in this novel and cost-

effective way.

• Ensuring that the nutrients produced by the fish are bioavailable to the plants. This

issue is related to the nitrification by bacteria, something which is much-discussed in

aquaponics literature, and which also forms part of the discussion in this thesis.

• Ensuring that the plants grown are either commercially viable, or the lessons learnt

from the experiments will be able to be applied to other plants for which there is a

market.

• Considering the future of fish farming in Iceland (and globally). There is a growing

public awareness of some serious environmental concerns regarding fish farming.

The use of wild caught fish as an ingredient in fish feeds is a big problem, and

Matorka is already experimenting with alternative feed sources. The possibility of

aquaponics being used as part of the fish food production loop in the future should

be considered. Similarly, the production of biodiesel from algae, the use of a local

renewable energy source (such as hydropower) for the lighting, and development of

similar plant or algae-based nutrient reuse systems for saltwater fish farms could all

be considered for future research.

• Keeping in mind that the system needs to be scaled up in size, grow marketable

products, be cost-effective, and that there is the potential for the reuse of more of the

water (even if that is never likely to be necessary at the Matorka site, it is still

something to consider for the potential applicability of aquaponics systems

elsewhere).

A low-cost, low-risk trial was designed in late 2012, to provide information useful for future

production of plants at a Matorka facility, and to demonstrate aspects of aquaponics theory

as a practical case study for this thesis.

Specifically, the trial aimed to:

• Characterise the water at various points in the Matorka production process and

determine the best water source(s) to use for hydroponic plant growth.

• Test various hydroponic systems and compare the productivity of plants grown under

these different conditions.

• Test the efficacy of the different hydroponic systems as a means of removing

nutrients.

• Calculate the optimal amount of plant biomass that should be planned to utilise the

nutrients in the Matorka waste-water stream.

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2.3.2 Experimental and analytical methods

Experiment design

After discussions with all the interested stakeholders, a trial was designed to answer the

questions listed above. The materials had to be locally available and either cheap or

repurposed. The trial needed to demonstrate a plant production system which could later be

scaled up to commercial size, and it also had to provide quantifiable data to scientifically

address some of the questions that backyard aquaponics enthusiasts don’t usually consider.

The diagram in Figure 2 illustrates the elements of the trial. The different treatments are

discussed below:

Three types of hydroponic systems were trialled (the three rows of experiment boxes). Four types of water were trialled in each of the hydroponic systems, including: A) a nutrient-rich control (commercial hydroponic nutrient mix), B) biofiltered aquaculture effluent, C) unfiltered aquaculture effluent, and D) a nutrient-poor control (tap water).

Figure 2. Experimental set-up.

A B C D

Water

At the time of the experiment, water moved in a systematic way through the Matorka facility,

as shown in Figure 3. The testing sites, aquaculture and freshwater inputs, and experiment

sources are shown in this diagram.

Figure 3. Schematic of the Matorka facility showing water flows, nutrient sources, and sampling locations. Diagram is not to scale nor geographically accurate, but it shows the main features of the Matorka facility at Fellsmuli, discussed in this thesis.

The water in the experiment had four different sources. Once set of three experiment boxes

(the nutrient-poor ‘tap water’ control set; D in Figure 2) used the fresh tap water available

on site, which was sourced from cold and hot underground sources on the farm (1 and 2 in

Figure 3).

Another set of three boxes (C in Figure 2) used water from the end of the ‘raceway’, a long

rectangular concrete tank, which was the last tank in the Matorka production system. Water

in the raceway tank was a combination of water from several other fish tanks, with a re-

oxygenation step, and added fresh hot water to raise the temperature. This combination of

pre-used water, combined with the high density of adult tilapia living in the raceway, gave

33

it the (estimated) highest concentration of nutrients at the site. Water from the raceway was

pumped (using an AquaKing HX-4500 Immersible Pump, capable of pumping 2000 L/hr)

via a 100mm black heavy-duty flexible pipe a distance of ~100m to a room previously used

as a hatchery, which was cleared and prepared for the experiments. The pumped water was

sent into a settling tray (the ‘pump tank’, number 6 in Figure 3), and then gravity fed into a

perforated PVC pipe which sprayed at equal rates into the three experiment boxes.

Some of the same nutrient rich fish-waste water was directed into a ‘biofilter’, which was

designed to expose the water to small stones with large surface areas able to be colonised by

nitrifying bacteria. The biofilter was constructed by Sveinbjörn Oddsson (Matorka

manager), and contains four chambers filled with various grades and amounts of local

pumice stone from the volcano Hekla. The water moves through the three chambers allowing

settling of any sediments and waste (physical filtration), and contact between the water

containing ammonia, and the bacteria which grows on the biofilter surfaces, which converts

the ammonia to plant-available nitrate. Figure 4 is a photograph of the biofilter used in the

experiment. Further discussion of biofilters is in section 3.1.4. The water from the biofilter

(B in Figure 2; 5 in Figure 3) was sprayed at equal rates into the three different types of

experiment boxes.

Figure 4. Biofilter viewed from above, with four chambers containing pumice. Settled sediment can be seen on the pumice, as well as a tube to an air-stone keeping the biofilter oxygenated.

Finally, water source A was the ‘nutrient-rich control’ source. This was a re-circulating

volume of water pumped around a small tank, which had a commercial hydroponic nutrient

solution mixed into it. The solution used was ‘General Hydroponics, FloraNova Grow’

(NPK 7:4:10), which lists the following nutritional makeup:

Total nitrogen 7.0%

Ammoniacal nitrogen 0.9%

Nitrate nitrogen 6.1%

Available phosphate (P2O5) 4.0%

Soluble potash (K2O) 10.0%

Calcium (CaO) 5.5%

Magnesium (MgO) 2.5%

Soluble sulphur (SO3) 5.0%

Iron (Fe) Chelated DPTA 0.1%

The nutrient mix was added at the suggested concentration on the General Hydroponics

website, 7.5 mL per US gallon (3.79 L).

In order to allow the nitrifying bacteria to grow in the biofilter and in the experiment boxes,

the experiment was set up, with water pumping through, and allowed to equilibrate for 28

days before the plants were transplanted.

Growing media

The three different experiment boxes in each water treatment contained 1) pumice stones

from nearby Hekla volcano, graded by a local company into 8-12mm pieces. 2) Hydroton, a

commercially available growth media made of expanded clay pellets usually used for

hydroponics, and 3) ‘deep water’ or ‘raft’ culture, essentially just the water with the plants

hanging above it so that their roots are mostly submerged.

For the pumice and Hydroton boxes, it was necessary to allow the growth media to dry out

periodically to allow the nitrifying bacteria to proliferate. Intermittent pumping of the inflow

water would have been too complicated given the different water sources and piping

methods, so a simple bell siphon valve was built for each box out of spare plumbing parts

and some purchased fittings. The bell siphons were constructed using instructions found

online (Fox, et al., 2010), and modified onsite as required for the experiment boxes (Figure

5).

35

Figure 5. Bell siphons built for each experiment box (from Somerville, et al., 2014; their Figure 4.58). Bell siphons similar to this diagram were constructed for each experiment box. The dotted line indicates the maximum water height (top of the standpipe, 22 cm in this diagram), and the dashed line indicates the minimum water height (base of the grow bed). A media guard was also installed around each bell siphon to improve performance, these are the black PVC pipes visible in Figure 6.

Figure 6 shows the experiment during the equilibration phase. The white PVC pipes carried

the water from the different sources. The black fittings in the centre of the Hydroton and

pumice boxes were where the siphons and gravel guards were fitted (as described above).

Figure 6. Experiment boxes during set-up and equilibration. Experiment boxes before planting, in the same positions as in Figure 2: back row contained Hekla pumice, centre row contained Hydroton, and closest row contained water, before the rafts were installed. From left to right, the different water treatments were: commercial nutrient mix, biofiltered aquaculture effluent, unfiltered aquaculture effluent, then plain tap water.

Plants

Three types of plants were chosen for the experiment, in consultation with the Matorka staff,

with consideration of the marketability of plants in Iceland, as well as growth rates and the

habit of the plants, since these would affect our ability to measure growth. Lettuce (Lactuca

sativa), basil (Ocimum basilicum) and spinach (Spinacia oleracea) were chosen.

Approximately 100 seeds of lettuce, basil and spinach were planted on the 26th of September,

in 20 mm inert coconut coir germination pads. Two seeds were planted in each pad. While

the germination rates for lettuce and basil were 98% and 91% respectively, only 12% of the

spinach seeds sprouted, so on the 7th of October, ~150 rocket seeds (also known as arugula,

Eruca sativa) were planted in the same manner. Although approximately 95% of the rocket

seeds sprouted, they were very small and fragile compared to the lettuce and basil seedlings

when they were transplanted into the experiment boxes on the 21st of October.

Figure 7 shows some of the seedlings growing in the coir pads prior to transplanting.

Figure 7. Rocket and lettuce seedlings growing in coconut coir germination pads prior to transplanting into the experiment boxes.

On the 21st of October (Day 0 of the plant growth experiment), 4 individuals of each plant

type were carefully separated from the other seedlings, washed of most of the coconut coir

fibres and transplanted into each experiment box. Ten individuals of each plant type were

also treated in the same manner but collected for measurement and weighing to give the

baseline data with which to compare the amount of plant growth at the end of the experiment.

37

The 12 individual plants (four each of lettuce, basil and rocket) were randomly arranged in

each experiment box, with care taken to prevent the plant leaves being hit directly by the

water flowing in to the boxes. For the pumice and Hydroton growing media, a small pit was

made in the stones by hand, and the roots of each plant carefully covered. For the raft

experiment boxes, the plants were placed in 35 mm diameter plastic baskets which were

hung through holes cut in nylon netting. Photographs of each experiment box were taken

each week to keep a record of plant health and growth.

All plants and microalgae were grown under a ‘MH Superveg PowerPlant Lighting

Systems’, 600W metal halide TT80 bulb, delivering 51 000 lumens, on a 12-hour timer to

simulate night and day.

Throughout the rest of the thesis, the different treatments are labelled as shown in Table 1.

Table 1. Labels and details of experiment variables.

Label Water Media Plants

TP Tap Pumice Basil x 4, Lettuce x 4, Rocket x4

TH Tap Hydroton Basil x 4, Lettuce x 4, Rocket x4

TR Tap Raft Basil x 4, Lettuce x 4, Rocket x4

UP Unfiltered Pumice Basil x 4, Lettuce x 4, Rocket x4

UH Unfiltered Hydroton Basil x 4, Lettuce x 4, Rocket x4

UR Unfiltered Raft Basil x 4, Lettuce x 4, Rocket x4

BP Biofiltered Pumice Basil x 4, Lettuce x 4, Rocket x4

BH Biofiltered Hydroton Basil x 4, Lettuce x 4, Rocket x4

BR Biofiltered Raft Basil x 4, Lettuce x 4, Rocket x4

NP Nutrient Pumice Basil x 4, Lettuce x 4, Rocket x4

NH Nutrient Hydroton Basil x 4, Lettuce x 4, Rocket x4

NR Nutrient Raft Basil x 4, Lettuce x 4, Rocket x4

Plant growth measurements

The ten individuals of each plant type that were used to develop the baseline data set, were

taken to Matís for analysis. First they were arranged on white paper for measurement,

photography, and subsequent image analysis to determine leaf area. Parameters measured

initially on each of the 30 plants were: number of leaves, root length, stem length and total

plant length. Five of each plant type were then cut into roots, stems and leaves, weighed,

dried for ~2 hours at 104 C, then reweighed to determine average pre-experiment fresh and

dry weights.

The program ImageJ was used to determine the leaf area of each plant. First, each photograph

was converted into an 8-bit grey-scale image (Figure 8), then the scale was set by drawing a

line along a known distance and having the program measure the number of pixels on the

line. The scale must be set for each image so it was necessary to include a ruler in each

photograph. The next step was to use the ‘set threshold’ feature to select the depth of colour

that best matches the leaf area. The parts of the image that corresponded to leaf areas were

selected individually and by using the ‘analyse particles’ function, then the area of each

highlighted part was automatically calculated by the program. A useful procedure for

measuring leaf area using ImageJ is explained by Miller (2011) and further information was

obtained from the ImageJ User Guide (Ferreira & Rasband, 2011).

Figure 8. Ten individuals of each species were analysed at Day 0 to provide a baseline. The photograph on the left was transformed into the grey scale image on the right by the program Image J, which was then used to calculate the average leaf surface area per plant at the start of the experiment. The same procedure was used at the end of the experiment on the four plants of each species from each experiment box.

At the end of the experiment period, the plants were removed from the experiment boxes

and again arranged on white paper for photography and image analysis. Each set of four

plants was labelled, photographed, measured (number of leaves, root length, stem length and

total plant length) and then the four individuals of each type from each experiment box were

39

grouped together for the fresh and dry weighing of the roots, stems and leaves. This resulted

in an average of the four plants of each type in each treatment. See Figures 8 and 9.

Figure 9. Example of dry weights of leaves, stems and roots being determined.

To display the growth in the plants over the course of the experiment, the difference between

the measurements at the start and end of the experiments were calculated as a percentage of

the starting measurement. For example, the starting average length (ls) of each plant species

was calculated at the start by measuring ten of each species. At the end of the experiment,

the four individuals of each species from each experiment box were measured again to give

a final average length (lf) for each of the 12 treatments. Then the following calculation was

used to determine the change during the experiment, which is expressed as a percentage so

that the naturally different sizes of the species did not affect the comparison of growth

between the 12 treatments:

D_total length = ((lf - ls) / ls) * 100

Equivalent calculations were also made for D_n of leaves, D_total leaf area, D_av leaf area,

D_root length, D_stem length, D_leaf length, D_fresh root mass, D_fresh stem mass,

D_fresh leaf mass, D_ fresh total mass, D_dry root mass, D_dry stem mass, D_dry leaf mass,

and D_dry total mass.

Selected results are shown in Section 3.3.1, and all results are included in Appendix C. When

error bars are shown, they are usually the range of results that make up an average displayed

on the chart. For example, in the total length calculation discussed above, ls and lf are

averages of ten and four plant lengths, respectively. The error bar would show the highest

and lowest values of the range measured.

Microalgae

As well as the plant growth experiments, a separate trial was conducted to test the conditions

required to grow a strain of marine microalgae which is being investigated by the University

of Akureyri and Matís in Akureyri, North Iceland, for its nutritional qualities. The algae,

known as Nannochloris sp., was selected because it is fast growing under a range of growth

conditions. An ideal strain for growing in the future would be selected based on the

usefulness of its products. For this experiment, four square plastic tubs were used and filled

with a measured amount of “Instant Ocean” powder to make up water with a salinity of

approximately 30 ppt.

In the first tub, plain salt water was used as the medium (equivalent to the nutrient-poor

control in the plant growth experiments). In the second and third tub, unfiltered and

biofiltered fish waste-water was used to fill the tubs, with the same quantity of salt. The

fourth tub contained the salt powder, and a nutrient mix previously determined to create the

ideal conditions for the microalgae to flourish (Rannveig Björnsdóttir, personal

communication, 2012).

All the tubs had a gently flowing airstone in place to ensure an adequate supply of oxygen.

The four tubs are pictured in Figure 10.

Figure 10. Microalgae tubs pictured during the experiment. Black tubes are connected to the airstones installed in each tub to oxygenate the water and stir the algal cells.

41

Microalgae growth determination

The microalgae were sampled approximately every 3 days (or as close to that as possible),

by using a disposable pipette to fill a 15 mL test tube. Prior to sampling, each container was

stirred with the airstone set in it, to ensure that the air bubbling had been successfully mixing

the water and that there was no clumping or uneven distribution of algal cells. The samples

were labelled, chilled to between 5-10 C, stored in the dark, and analysed as soon as possible

(usually within 24 hours) in the Matís labs in Reykjavik.

To quickly estimate the growth in algal cell density over time, without counting the cells

under the microscope, the commonly used (Myers, et al., 2013; Rocha, et al., 2003) visible

light spectrometry Optical Density (OD) technique was used. A calibration curve for

converting OD into Nannochloris sp. cell density had been previously determined by Matís

and University of Akureyri researchers (Rannveig Björnsdóttir, personal communication,

2012), so given similar culturing conditions in this experiment, the OD could be calculated

by measuring the light absorbance at 640nm and comparing this with the previously

determined calibration curve.

After about two weeks of microalgae growth, it looked as though the measurement of OD at

640 nm was not revealing the true differences between the amounts of growth in each

container, so more absorbance measurements were undertaken at different wavelengths, and

5 mL sub-samples of each sample were taken, centrifuged and dried to give an indication of

the biomass in g L-1 in each container on each sampling day.

At the end of the microalgae experiment, the total biomass that had grown in each container

was calculated by taking a 50 mL sample from each container, centrifuging and drying it to

give the total dry biomass per litre in each treatment. e.g. Figure 11.

Figure 11.Example of algal filtrate samples after filtering and drying. Algal biomass was determined by sampling the algal cultures, centrifuging, and drying out the filtrate for weighing.

Nutrient and water analysis

The pH, temperature and Dissolved Oxygen (DO) of the water in the experiment boxes were

measured once a week with a pHep Tester (Hanna Instruments, Rhode Island, USA) and an

OxyGuard Handy Polaris v. 3.03 EU (OxyGuard International A/S, Birkerod, Denmark).

The same characteristics of the water at various points around the Matorka facility (See

Figure 3) were also measured at the same time samples were taken for nutrient analysis.

Each week, 500 mL samples from each experiment box (as well as some other system water

samples) were collected in clean plastic bottles, cooled to ~4 C and transported to Matís for

analysis as soon as possible after sampling. Within 24 hours of sample collection, sub-

samples of known volumes (usually 250 mL) were filtered with 0.7 μm pre-weighed

Whatman glass-fibre filter papers in a tap-fitted vacuum filter device. The filter papers were

dried for 1-2 hours (and until no more loss of mass was recorded) at 104 C, cooled in a

desiccator and the dry mass of the suspended solids calculated as a mg L-1 figure. This

analysis, based on the Matís draft Total Suspended Solids laboratory protocol (Knobloch,

2012a), resulted in the Total Suspended Solids (TSS) information for each sample.

Fifteen millilitres of filtrate of each sample was collected in a plastic test tube and either

frozen or analysed immediately. Before analysis, samples were filtered with 0.2 µm GF

filters. Nutrient analysis was carried out on a FIAlab 2500 spectrometer with an ASX 260

43

autosampler, and custom software, in the Matís laboratories, Reykjavik (Figure 12). The

FIAlab system is capable of analysing a high number of samples in a short amount of time,

relative to traditional colourimetric analysis. FIA stands for Flow Injection Analysis, and

one of the main advantages FIA has over other analytical techniques is that less than 1 mL

of sample is required for each analyte. The four different analytical methods used are

described below.

Figure 12. FIAlab spectrometer equipment at Matís, Reykjavik.

For each analyte, variations need to be made to the setup of the system, with different fittings,

connections, reagents and procedures required (FIAlab Instruments, n.d.). Examples of these

variations are different-sized flowcells, different lengths of sample and mixing tubing,

different pump and heater settings, and various concentrations of standards which were

prepared and run with each batch as quality control. The details for the main variables for

each technique are included below to try to make the analyses repeatable, however details

about FIAlab operation (e.g. software controls, reference scans, autosampler setup) and

chemistry details for standard and reagent preparations are not included.

FIAlab spectrometer

Autosampler with samples ready to analyse

Reagents, surfactant, distilled H2O (or carrier solution), waste jar

Results sent to FIAlab software for plotting as spectra and analysis

Nitrite: Nitrite concentration in the FIAlab method is determined by reacting the nitrites in

the sample with sulphanilamide to form azo dyes. These then couple with N- (1-Naphthyl)

ethylenediamine dihydrochloride to form a magenta coloured solution (O'Dell, Method

353.2 Determination of Nitrate-Nitrite Nitrogen by Automated Colorimetry, 1993). The

spectroscope is used to quantify the dye solution at 540 nm, the absorbance of which is

proportional to the nitrite present in the initial sample (FIAlab, n.d.a). To calculate the

relationship between nitrite concentrations and the colour of the dye solution, a calibration

curve is created from known nitrite concentrations in calibration standards (O'Dell, Method

353.2 Determination of Nitrate-Nitrite Nitrogen by Automated Colorimetry, 1993).

Analytical details (Knobloch, 2012b; FIAlab, n.d.a):

Carrier: DI-water (salt water matrix would be required for salt water samples) with added surfactant (Brij 35).

Reagent 1: None (plug reagent 1 intake)

Reagent 2: Colorimetric sulfanilamide solution (store in dark bottle)

Standards: Stock solution = 1 g/L NO2-N made from KNO2. Dilute stock solution to standards containing 0.1, 0.05 and 0.025 mg/L NO2-N. Suitable matrix must be used (i.e. DI-water).

Setup (for low concentration assays): 15 cm flowcell; 12” white sample loop (0.03” internal diameter); 5” white column loop

Pump: 60%

Heat: off

Wavelengths: 540 nm primary, and 650 nm reference

Nitrate: Nitrate concentration is determined in the same way as for nitrite, but with an added

step, of using a cadmium column to catalyse the reduction of nitrates into nitrites first. Nitrite

concentration (that was originally present plus the reduced nitrate) is then measured using

colourimetry of the dye produced by the reaction with sulfanilamide, as above (O'Dell, 1993;

FIAlab, n.d.a). The difference between the concentrations of nitrite (with and without the

reduction step) is the nitrate concentration. Analytical details (Knobloch, 2012c; FIAlab,

n.d.a):


Reagent 1: 1.6 M ammonium chloride buffer

Reagent 2: Colorimetric sulfanilamide solution (store in dark bottle)

45

Standards: Stock solution = 1 g/L NO3-N made from KNO3. Dilute stock solution to standards containing 2, 1 and 0.5 mg/L NO3-N. Suitable matrix must be used (i.e. DI-water).

Setup (for mid to high concentration assays): 1 cm flowcell; 2” white sample loop (0.03” internal diameter); cadmium column

Pump: 60%

Heat: off


Phosphate: This method is for the common form, orthophosphate (PO43-), which is soluble

in water. The method analyses reactive phosphorus (hydrolysed orthophosphate) which can

be directly determined with no pre-treatment (FIAlab, n.d.b). No pre-treatment to convert

organic phosphorus compounds to orthophosphate was undertaken as described by O’Dell

(1993). Orthophosphates react with molybdate anions to form a phosphomolybdate complex.

This is then reduced by ascorbic acid to create a molybdenum blue species which is detected

by the spectrometer at wavelengths between 700 nm and 900 nm (FIAlab, n.d.b). The colour

is proportional to the phosphate concentration. The following settings were used (Knobloch,

2012c; FIAlab, n.d.b):


Reagent 1: 6 mM ammonium molybdate

Reagent 2: 300 mM ascorbic acid

Standards: Stock solution = 0.1 g/L PO4-P made from KH2PO4. Dilute stock solution to standards containing 1.6, 0.8 and 0.4 and 0.2 mg/L PO4-P. Suitable matrix must be used (i.e. DI-water).

Setup (for low concentration assays): 15 cm flowcell; 12” white sample loop (0.03” internal diameter); 5” white column loop

Pump: 60%

Heat: Water bath to 55 C and place green mixing coil inside


Ammonia (TAN): The FIAlab recommended method for low ammonium levels was used. It

is known as the salicylate method, and it involves a three-step reaction sequence (FIAlab,

n.d.c). The first reaction converts ammonia to monochloroamine by adding chlorine (from

household bleach). The monochloroamine reacts with salicylate to form 5-aminosalicylate,

which is oxidised in the presence of sodium nitroferricyanide to form a blue-green dye. The

spectrometer measures the absorbance of light by the dye at 650 nm, and a calibration curve

created with known standards helps the software convert the colourimetry result into a

concentration (FIAlab, n.d.c). The laboratory setup was based in the FIAlab standard

method, and experimentation at Matís:

Carrier: DI water (salt water matrix would be required for salt water samples) with added surfactant (Brij 35).

Reagent 1: Hypochloride solution made from sodium hypochloride (bleach), NaOH and DI water. Reagent 1 must be prepared daily.

Reagent 2: Salicylate catalyst solution made from sodium salicylate, sodium nitroferricyamide, NaOH and DI water.

Standards: Stock solution = 1 g/L TAN made from NH4Cl. Dilute stock solution to standards containing 1, 0.5 and 0.25 mg/L TAN. Suitable matrix must be used (i.e. DI-water).

Setup (for low concentration assays): 15 cm flowcell; 36” white sample loop (0.03” internal diameter); short green tubing for bridging connection B.

Pump: 45%

Heat: Water bath to 60 C and place green mixing coil inside


Quality control procedures are included in the FIAlab methods and the Matís protocols. For

example, at least 10% of samples are quality control samples, including blanks and standards

of known concentration, sample replicates, and samples to allow drift correction. For each

batch of samples, drift corrections were carried out, and the blanks and standards were

regularly checked for discrepancies. If a batch of results was accepted, an error calculation

was made, based on the difference between the known laboratory standard concentrations,

and the measured concentrations. The highest errors for each nutrient method were selected

to show as the error bars in the charts displaying nutrient results.

Statistical analysis

Simple statistical calculations were carried out using Excel to examine the significance of

the results.

To determine whether the different experimental treatments (pumice, Hydroton, raft,

unfiltered water, biofiltered water, plain control, nutrient control) resulted in significantly

different plant growth characteristics, a series of t-Tests were performed between the

different populations (treatment results). Because the data sets had different variances, in

47

each case, the ‘t-Test: Two-Sample Assuming Unequal Variances’ was used to test the null

hypothesis, that the two populations being tested have the same mean and so are not different

from each other. To test significance, in each case, the two-tailed p-value was examined, and

where it was below the critical value of 0.05, the null hypothesis was rejected. The p-values

from each of the t-Tests are presented in Section 3.3.1.

To test whether the changes in water quality parameters measured over the course of the

experiment showed significant trends (i.e., whether the nutrients measured weekly were

changing linearly, or were no different from random), a regression analysis (using the Excel

data analysis ‘regression’ function) was performed on each data set. A p-value and r2 statistic

was generated for each set of measurements (each nutrient, pH, and TSS data set for the

biofiltered effluent, the unfiltered effluent, the three biofiltered experiment boxes and the

three unfiltered experiment boxes). Where the p-value was below 0.05, the null hypothesis,

that the slope coefficient was zero (i.e. there was no linear trend in the data), was rejected.

The complete set of p-values and r2 values for each of the variables is presented in Section

3.3.2. Where a significant trend was found, this is noted on the relevant graph displaying the

water quality parameters in the same section.

Where practical, data are graphed with error bars to show the range of results (for averages,

e.g. microalgae biomass measurements), or the precision of the technique (for nutrient

analysis results).


By design, this was a small, short, low risk experiment intended to explore the hypothesis

that aquaponics would be a suitable addition to Matorka’s business. The results could have

been more robust and useful to other organisations if the experiment had continued for a

longer period (for example, ~100 days until harvest of the vegetables would have been

possible).

So that the cost of experimental set-up was low, everything was designed to fit under one

grow lamp and be built out of repurposed or cheap materials. A commercial scale aquaponics

set-up for Matorka would be bigger and have some more professional parts. For example,

the siphon valves were hand built and tricky to perfect. There were times when the flood and

drain mechanism wasn’t working well, and so nitrification processes may not have been

optimal.

As discussed in Section 4, the flow-through design of the system is not a typical aquaponics

design (in which the whole idea is to reuse the water for the fish after the plants have cleaned

it), and there are theoretical disadvantages to this methodology related to the lower amounts

of colonising bacteria in the system (Somerville, et al., 2014). It is uncertain whether this

difference becomes negligible over time because of compensating high surface area of

various system elements, and/or whether lower nitrification rates would have affected the

experimental results in this case.

One of the resulting difficulties of the flow-through design is that concentrations of nutrients

are lower than in traditional water quality analysis, so more difficult to measure. This was

partially addressed by the FIAlab system, however the analysis was something of a trial for

Matís (Ragnar Jóhannsson, personal communication, October, 2012) and had not been

perfected as a standard laboratory method at the time (late 2012). The phosphate and the

TAN procedures were particularly difficult to troubleshoot, with dozens of repeated

measurements, re-sets, re-calibrations and adjustments required. The results were suitable

for the discussion of the research questions for this thesis, but with more time to work in the

laboratory, more samples and a higher research budget, greater accuracy and confidence in

the analysis could have been obtained.

In general, limitations of colourimetric and micro-assay methods are acknowledged by

experts, including: the requirement (and potential error) of having to have equipment and

reagents extremely clean and contaminant-free, especially for TAN measurement (O'Dell,

1993); the possible incomplete reduction of nitrate to nitrite with the cadmium column

method (Stephen Knobloch, personal communication, October 16, 2012); a possible error

with the reference scan measurement in the FIAlab system, resulting from the wrong length

of sample tube (Ragnar Jóhannsson, personal communication, October 30, 2012); the

potential for reagents or standards to deteriorate over time at an unknown rate (FIAlab , n.d.);

and the possibility of nutrient levels in samples changing due to ongoing bacterial

transformations if they are not stored properly or analysed immediately.

49

2.4 SWOT analysis

2.4.1 Objectives

Strengths, Weaknesses, Opportunities, Threats (SWOT) analysis is a framework commonly

used to analyse companies, industries, and even the performance of individuals. It is a

strategic tool used most commonly in organisational decision making (Chermack &

Kasshanna, 2007), but has found wide application in all fields including natural resource

management (e.g. Kajanus, et al., 2012; Robins & Dovers, 2007).

2.4.2 Method

A SWOT analysis was originally used to brainstorm a structure and theme for this thesis. It

was suggested that the categories of strengths, weaknesses, opportunities and threats would

make a useful format for a discussion of the aquaponics industry. After drafting and editing,

however, it became apparent that, as some authors have noted (Kajanus, et al., 2012) a

SWOT analysis can be underwhelming if it just generates a list of seemingly equally

weighted factors, with no hierarchy of importance. It was also a subjective list collated by

one person, which has been described as a misuse of a tool best applied collaboratively

(Chermack & Kasshanna, 2007). For these reasons, and to avoid repetition, the SWOT

brainstorming results do not have their own section in the Results chapter, but were

combined with a literature review of relevant articles to generate the discussion sections, 4.2

Aquaponics Strengths and Opportunities, and 4.3 Weaknesses and Threats.


The SWOT analysis in this thesis is simply a way to frame and structure the discussion. As

SWOT ‘opportunities’ and ‘threats’ encourage the analyst to consider future scenarios

(Koch, 2000), consideration of the future of the aquaponics industry also resulted in the

discussions in sections 4.5 Improving Aquaculture, 4.6 Sustainable Development and 4.7

Strategic Planning.

As noted, using only one person’s ideas narrow the true potential of a SWOT analysis, but

considering the published opinions of multiple aquaponics practitioners has hopefully

minimised this problem.

To build on a SWOT analysis and overcome the criticism that it generates an incomplete

qualitative list with no end-use in mind (Kajanus, et al., 2012), some users are now

incorporating Multiple Criteria Decision Support (MCDS) methods with the framework.

These techniques, of which the Analytic Hierarchy Process used in A’WOT is an example,

systematically evaluate SWOT factors to obtain quantitative information (Kajanus, et al.,

2012). It is beyond the scope of this thesis to undertake more in-depth analysis of the SWOT

factors described in Sections 4.2 and 4.3. However, for aquaponics decision-making or

industry strategic planning, a combined SWOT and MCDS analysis would be a fruitful

exercise, and it is recommended in Section 4.7 Strategic Planning.

51

3 Results

3.1 Technical literature review

3.1.1 The theoretical system

The literature review below focuses on the types of systems that are commonly built, and

the scale (backyard, community or commercial) that the system is suitable for. The sections

address the common elements to all systems, which must be considered by anyone planning

an aquaponics set-up: Types of system, hydroponics techniques, water chemistry, filtration

concerns, fish (as well as fish feed and food safety issues relating to the fish as edible

products), the plants that can be grown, pests in aquaponics, and energy requirements.

Overarching elements like technology and where aquaponics advice can be found are also

discussed briefly. Figure 13 shows these elements connected in a theoretical aquaponics

system.

Lettuce in pumice, October 2012 (I. Flett)

Figure 13. The different elements of aquaponics that someone planning an aquaponics set-up should consider. The circles represent connected internal system elements, the arrows are other important considerations. All the elements have their own section in the literature review below.

3.1.2 Types of systems

The aquaculture side of aquaponics operations is usually built as either a Recirculated

Aquaculture Systems (RAS) or an ‘open’ system. Open aquaculture is based on the simple,

traditional method of fish farming, often in small natural or man-made ponds cut off from

rivers, in farm dams, or in pens in larger lakes. In open aquaculture systems such as these,

the farmer does not have much control over the water quality in the system, but there are

often natural flushing mechanisms (for example, annual river flooding) which allow

occasional refreshing of the water. RAS systems, on the other hand are ‘closed’ production

systems, where all the water quality parameters and characteristics are known and controlled.

These systems are land-based, and usually fresh water, and must be indoors or protected

from precipitation inputs. Managers control the feed inputs, water chemistry and

temperature, but they must also provide the filtration system and waste treatment, something

which would be taken care of by an open, self-flushing system.

Another sustainable aquaculture technique with a lot in common with aquaponics, is usually

carried out in marine waters. It is known as Integrated Multi-trophic Aquaculture (IMTA).

This is normally an open marine system but is also practiced with freshwater (FIMTA) and

on land (Bakhsh, et al., 2014). Some classifications put aquaponics as a branch of IMTA,

perhaps the ‘backyard’, less professional version (Thomas, 2011), some say that a system is

53

aquaponics if it involves the cultivation of microbes (Bakhsh, et al., 2014), while some

classifications just make a fresh/marine distinction. Four broad ‘varieties’ of aquaponics are

summarised below.

Open/Pond aquaponics

The history of aquaponics originated with both Asian and Central American farmers

discovering that they could grow fish at the same time as they fertilised useful vegetable

crops. Including fish and crustaceans in paddy fields for fertilisation is still a standard rice

cultivation method all over Asia. Floating rafts for growing marketable vegetables in catfish

and tilapia ponds is a common technique for community and commercial food production,

particularly in Bangladesh and Southeast Asia (Pantanella, 2008; Somerville, et al., 2014).

Closed/RAS aquaponics

For commercial scale aquaponics production, RASs are the most commonly used systems

for the fish culture element. Water is pumped in a loop from the fish tanks to a filtration

and/or biofilter stage, then on to the hydroponic section for the plants to strip the excess

nutrients from the water before it is sent back to the fish in a closed loop. For the hydroponic

setup, plants can either be grown in a media, on rafts or in separate troughs with water

flowing past (all these hydroponic techniques will be described in the next section). RAS

systems are sensitive to water chemistry fluctuations, and require some technical

understanding and custom equipment.

Urban aquaponics

Aquaponics has potential to improve existing urban hydroponics operations, as a part of

planned urban green-roof initiatives (Wilson, 2006). Green roofs have many positive

environmental effects such as reduced city temperatures, energy savings, both direct (from

reduced cooling demand) and indirect (e.g. reduced food transport and agrochemical

production) reduction in greenhouse gases, particulates and sulphur dioxide, and reduction

of storm water flows resulting in fewer sewer overflow events, and therefore savings on

storm water management, erosion control and clean-up costs (BCIT, n.d.).

Urban aquaponics is also exciting because of its potential for providing a socially equitable

and environmentally sustainable food production method for cities, which are predicted to

bear the brunt of world population growth (Laidlaw & Magee, 2016). Urban agriculture in

general is expected to have excellent potential for solving many sustainability challenges

(De Zeeuw, et al., 2011).

A project called ‘Aquaponic Urbania’ was established in Copenhagen, Denmark. It is a

rooftop greenhouse designed to utilise ‘wasted’ solar energy, support the municipality’s

goals of increasing the number of green roofs and becoming CO2 neutral by 2025 (Klandal,

2012). The aim is to improve the economic viability of urban agriculture so that it can help

contribute to food requirements of the rapidly urbanising and growing world population.

Other successful urban aquaponics systems (commercial and research) have been developed

in Switzerland, The Netherlands and elsewhere in Denmark where the Ministry of the

Environment has been supportive (Skar, et al., 2015). There are numerous urban aquaponics

facilities in the United States, where the EPA has reviewed urban zoning codes to facilitate

local food production, and a couple in Australia (Laidlaw & Magee, 2016).

Marine and salt systems

Just as exciting as the freshwater aquaponics systems that most backyard enthusiasts focus

on, are saline systems growing marine fish and shellfish species alongside macro- and micro-

algae, or salt tolerant plants. As a way of using the nutrients produced by finfish aquaculture,

as a method of producing protein rich material to replace wild fish meal, and as a good source

of omega oils for human consumption, saline aquaponics have great potential (Ibrahim, et

al., 2015).

A project in Florida, USA demonstrated the feasibility of growing Florida red drum

(Sciamops ocellatus), sea purslane (Sesuvium portulacastrum) and saltwort (Batis maritima)

in a custom built saline aquaponics system (Boxman, et al., 2015). The three species had a

local market and a grant was obtained to fund the project. The setup included a swirl

separator, a sand filter, two sump tanks, an upflow media filter and a moving-bed bioreactor

in addition to the fish culture tanks and plant raceways (modified raft technique). Chemical

measurements were taken and adjustments made to improve the nitrification. The research

successfully demonstrated the function of the filter elements, and that marketable saline

species can be grown in aquaponics systems (Boxman, et al., 2015).

55

Some plants like tomatoes, quinoa and pearl millet are salt tolerant under some conditions.

Plants like Salicornia sp., sea beat and salsola are all known halophytes with small markets

but good yields and potential (Pantanella, 2012).

Saline aquaponics, or IMTA has been said to be a solution to the aquaculture sector’s major

challenges (Granada, et al., 2015). It is the potential for mitigating aquaculture’s wasted and

polluting nutrient outputs, and for increasing the complexity in the systems in order to mimic

ecological systems and add value that makes people so hopeful about IMTA.

3.1.3 Hydroponics techniques

There are quite a big variety of systems described in the literature, all with different setup

specifications, and their own advantages and disadvantages.

Nutrient Film Technique

Nutrient Film Technique (NFT) is a growing system often used in hydroponic systems, in

which pipes or gutters carry a shallow flow of nutrient-rich water (the film) around the

system. The plants grow directly in the gutters, with their roots partially submerged

(Lennard, 2010). Compared to the other two common aquaponics plant-growing system

discussed below, NFT uses lower water volumes, which means nutrient concentration gets

higher, faster, and the systems may be smaller and lighter, so perhaps more useful for

backyards or urban areas. It is essential that good filtration is employed in NFT, which is not

so important in growth media systems, as will be explained (Somerville, et al., 2014).

Some experiments have shown reduced growth in NFT compared with other methods,

perhaps because the roots are not in contact with the nutrient source for as long. In the other

systems, the roots are submerged most of the time (Lennard, 2004).

The shallow depth of NFT style systems means that they can be stacked on top of each other,

in the manner of a vertical garden (Patillo, 2017), and the common PVC pipe setup means

that the nutrient-rich water can be arranged to flow along a path which can wind around

otherwise unused spaces.

Raft or deep-water systems

In raft systems, the plants are hung over flowing water, or float directly on ponds or tanks.

Often Styrofoam or timber boards sit on top of the water, with holes cut for the plant roots

to grow through (Somerville, et al., 2014). They are common in commercial systems because

of their simplicity, reliability and easy cleaning. Because the plant roots are submerged, even

if the water flow stops for some reason, the plants are unlikely to die quickly (Patillo, 2017).

A recommended depth for the water is 30-60cm (Patillo, 2017; Diver & Rinhehart, 2010).

Oxygen needs to be restored to the water either before entering the raft system or via air-

stones in the containers, and as with the NFT style systems, a biofilter is considered essential

(Somerville, et al., 2014).

Growth media systems or ‘Flood and Drain’

These are the most commonly used setups. When community members discuss ‘grow beds’

they are talking about plant growing beds filled with a growth media other than soil. Water

flushes through the grow beds frequently, and the surfaces of the growth media are

eventually covered in a ‘biofilm’ of nitrifying bacteria. In this way, the grow beds function

as biofilters, and in small systems, also work as mechanical filters of the waste, which can

result in clogging (see the next section for further discussion of filtration; Somerville, et al.,

2014).

The growth media used in a flood and drain system can be any kind of gravel. Expanded

clay pellets are popular because they are light and easy to move around. A material that has

a high surface area to volume ration is advantageous because the biofilm has more surfaces

to grow on. Somerville and co-authors (2014) compare the different common media types,

and list pumice stone as having a surface area of 200-300 m2/m2, and expanded clay pellets

similar at 250-300 m2/m2. Both have neutral pH, are light weight, have ‘medium’ water

retention and plant support properties, and are considered easy to work with (Somerville, et

al, 2014).

To use growth media, a flood and drain methodology is recommended, where the grow beds

are filled with water and emptied periodically, because regular air flow around the roots

replenishes oxygen for bacteria and plants. This can be done with a continuous flow of water

into the grow beds, combined with a siphon that automatically dumps the water periodically.

57

Alternatively, the pump can be put on a timer so that water flows in and then drains out of

the beds on a cycle. Commonly in backyard aquaponics, bell siphons are constructed out of

PVC pipe (See Section 2.3.2). It can be tricky to set them up for regular drainage (but not

constant siphoning), but this method uses less power than regularly turning a pump on and

off.

Drip irrigation

This technique is similar to NFT, except the plants are grown in a growth media in a pot.

Small amounts of water are dripped into the pots, and this drains out into a pipe that

reconnects the used plant water to the fish tanks (Patillo, 2017). Because of small diameter

pipes, clogging and blocking can be a problem, but the technique is effective for some plants,

such as tomatoes and vines.

Vertical systems

Recently, a lot of vertical systems have become commercially available, aimed especially at

people with small gardens in urban areas. A range of plants grow well in a tower structure,

where the roots are inside and in contact with the water running down inside. There are also

attractive vertical garden setups to cover a wall inside or outside the house. Other vertical

setups are modified NFT, raft or growth media systems.

3.1.4 Water chemistry

One of the most important elements of the aquaponics system is the healthy community of

nitrifying bacteria that is required to transform ammonia from fish waste into nitrite, which

is less toxic than ammonia, and then nitrate, which plants can use for growth (Nelson, 2008).

If ammonia is not converted by the bacteria, it builds up in the water and becomes toxic to

the fish. This conversion process is natural, occurring in all ecosystems; the natural process

can be amplified for a RAS by using a ‘biological filter’, or biofilter (Heath, et al., 2010). A

biofilter is a unit containing a porous media that is well aerated, with optimal temperature,

pH and DO levels, and importantly, plenty of surface area for the bacteria to grow on

(Nelson, 2008). Most small aquaponics systems do not require a separate biofilter because

the media or the rafts and other parts of the system do the same job, however systems using

NFT to grow the plants do require biofilters since there is not usually enough surface area

for adequate bacteria colonisation (Nelson, 2008).

Nitrogen is introduced into the system as protein in fish feed. The fish excrete it as aqueous

ammonia. The process of nitrification occurs in two steps, with the help of autotrophic

bacteria. The first is the conversion of total ammonia nitrogen (TAN, i.e. NH3 and NH4+) to

nitrite (NO2-) by ammonia oxidising bacteria (AOB) such as Nitrosomonas, and the second

is the conversion of nitrite to nitrate (NO3-) by nitrite oxidising bacteria (NOB, mainly

Nitrobacter spp. and Nitrospira spp.; Hu et al, 2015). The two conversions are represented

with the following equations (Heath, Tait, & Grant, 2010):

55 NH4+ + 5 CO2 + 76 O2 C5H7NO2 + 54 NO2

- + 52 H2O + 109 H+ (Nitrosomonas)

400 NO2- + 5 CO2 + NH4

+ + 195 O2 + 2 H2O C5H7NO2 + 400 NO3- + H+ (Nitrobacter)

Nitrite ion Ammonia ion Nitrate ion

Additional nitrogen escapes the system as nitrous oxide (N2O), through the bacterial

nitrification process, and also during denitrification which occurs if anoxic conditions

develop in any part of the system (Hu, et al., 2015). N2O is a greenhouse gas, which

aquaculture and aquaponic facilities are potentially emitting in varying quantities (Hu, et al.,

2015).

Scientists have calculated that it takes 4.57 g of oxygen and 7.14 g of alkalinity (usually

CaOH or KOH) for bacteria to oxidise 1 g of nitrogen in the ammonia form (Heath, et al.,

2010). The same authors (2010) warn: “Other organisms occupy the biofilter, such as

heterotrophic bacteria, protozoa and micrometazoa. Heterotrophic bacteria grow

considerably faster than nitrifying bacteria and compete for space in the filter. Unlike

nitrifying bacteria, these other organisms consume degradable organic compounds. To

minimise this competition for space and oxygen it is important that the water entering the

biofilter be as clean as possible.”

Nitrifying bacteria work best when pH is around 7.0, which is also approximately the

midway point between the ideal pH levels of the fish and the plants (Nelson, 2008). Since

the nitrification process also generates H+ ions (see equations above), the pH is being

lowered all the time (the rate at which this occurs depends on the alkalinity, buffering

capacity and temperature of the water being used), and research has shown that nitrification

slows as the pH drops and will stop at below 6.0.

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In experiments conducted in trickling biofilter systems containing perlite medium, with no

plants or fish, but controlled pH and measured nutrient levels, it has been shown that total

ammonia concentration decreased from 5 to 0 mg/L in 12 (pH 8.5), 20 (pH7.5), and 20-24

(pH 6.5) days after the introduction of nitrifying bacteria (Tyson, et al., 2004). In these

experiments, Nitrite became measurable at 8 (pH 8.5), 16 (pH 7.5) and 20-24 (pH6.5) days.

No nitrification occurred in the biofilters at pH 5.5.

Because it can take 20-30 days for the bacteria to colonise and stabilise, some growers ‘jump-

start’ their systems by adding ammonia to the water before adding the fish, or adding

commercial bacteria mix after the fish have been introduced. Alternatively, growers can wait

for natural bacteria to colonise. This will be indicated by an initial raising of ammonia levels

for the first 10 days, then rising nitrite with lowering ammonia (Nitrosomonas conversion),

and then falling nitrite levels and stabilisation (Nitrobacter conversion; Nelson, 2008).

If the biofilter malfunctions, or in an aquaponics system where there is no biofilter, levels of

nitrite or (less commonly if there are plants in the system) nitrate could build up and become

toxic to the fish. Nitrite poisoning in freshwater fish causes a condition known as ‘brown

blood disease’ caused by the nitrite reacting with haemoglobin in the blood, preventing it

from carrying oxygen (Heath, et al., 2010).

The New Zealand seafood industry has published safe limits of nitrite and nitrate for

aquaculture species commonly grown there (Table 2).

Table 2. Nitrate and nitrite guidelines for some aquaculture species (from Heath, et al., 2010). The table shows tolerance limits for some species tested in New Zealand.

Species Lifestage Nitrite limits (mg/L) Nitrate limits (mg/L)

Chinook Salmon All Freshwater <0.01 <400

Grass Carp All Ideally <0.03 No guideline

Paua All <0.1; no data available – estimate only (levels of 0.5 have been shown to affect growth

No guideline, generally not a concern

Pacific Oyster All Very tolerant to high levels Not a concern. Used by phytoplankton who remove them from the water, as a source of nutrients

Red Rock Lobster All <1.0 <100 mg/L for short term exposure and <50 mg/L for long term exposure

Optimal conditions

With all aquaponic systems, a compromise for optimal conditions has to be made since the

plants, fish and bacteria have different tolerances. Somerville et al. (2014) present

generalised system tolerances, based on an extensive review of the literature (Table 3).

Table 3. Optimal water quality parameters for the different parts of an aquaponics system (Somerville et al., 2014)

Organism Temp

(oC) pH

Ammonia

(mg/L)

Nitrite

(mg/L)

Nitrate

(mg/L)

DO

(mg/L)

Warm water fish 22-32 6-8.5 < 3 < 1 < 400 4-6

Cold water fish 10-18 6-8.5 < 1 < 0.1 < 400 6-8

Plants 16-30 5.5-7.5 < 30 < 1 - > 3

Bacteria 14-34 6-8.5 < 3 < 1 - 4-8

Ideal aquaponics compromise

18-30 6-7 < 1 < 1 5-150 > 5

To maintain optimal pH conditions, when the nitrification process is constantly lowering pH,

most aquaponics growers add CaOH and/or KOH, which both raises the pH and provides

supplemental calcium and potassium for healthy plant growth (Nelson, 2008).

Maintaining high DO levels in the culture water is important for plants, fish and ongoing

nitrification (Rakocy, et al., 2008). The common methods of water aeration are diffused air

systems, consisting of an air compressor outside the tank and a diffuser in the water, water

pumps, mechanical aeration devices and for smaller systems, airlifts can double as pumps to

move water around the system, and aerators (Koeniger, 2008; Pade, 2008). Somerville et al.

(2014) note that for small-scale systems, as long as there is some method of aeration,

stocking densities are not too high, and fish behaviour can be monitored to check for signs

of distress, there is no need to invest in expensive DO monitoring equipment. Regular

monitoring of water chemistry with water test kits, however, is recommended, especially

during the set-up phase (Somerville, et al., 2014).

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3.1.5 Filtration

Mechanical filtration is a process that removes the solid waste from the RAS water. It is

different from biofiltration, which is the process of converting ammonia to nitrate, discussed

above. Mechanical filters are also known as solids filters or clarifiers, and while they are not

always required in small media-filled systems, they are important for NFT and raft systems

because if solids build up, the water can become toxic, the plumbing can be clogged with

waste and the plant roots can be covered in fine solids, reducing their nutrient uptake ability

(Nelson & Pade, 2007).

In small-scale systems, suspended solids are usually left in the water, since the biofiltration

process allows valuable elements and trace minerals to be extracted from the waste.

However, care has to be taken so that sludge doesn’t build up and become anaerobic

(Rakocy, et al., 2008). Often, a biofilter is used as a mechanical filter as well, or the grow

beds act as both. In this situation, it is necessary to clean the biofilter medium and/or the

growth media, and keep the media oxygenated, to prevent anaerobic conditions (Somerville,

et al. 2014). This is despite the fact that the cleaning will remove the biofilm and temporarily

reduce nitrification.

The University of the Virgin Islands aquaponics system (one of the key demonstration

facilities at a commercial scale) uses a conical clarifier, which draws the settled solids from

the bottom of the fish tank and past a series of baffles which cause the water to change speed

and drop the suspended particles. Tilapia fingerlings are also used as part of the design within

the clarifiers – they are introduced to feed on suspended solids to reduce waste (Rakocy, et

al., 2008). Alternative filtration methods are settling basins (commonly used in smaller

systems) or settling tanks, drum filters, reciprocating filters and swirl separators.

3.1.6 Fish

The fish species that are usually used for aquaponics are the same as those developed or bred

for aquaculture. Table 4 is taken from Bakhsh et al (2014), and lists the commonly selected

species in tropical and temperate water.

Table 4. Fish and invertebrate candidates for freshwater Integrated Multitrophic Aquaculture operations in tropical and temperate regions (after Bakhsh et al, 2014).

Tropical (15-30oC) Cold to Temperate (5-20oC)

Tilapia Trout

Catfish Arctic char

Carp Silver perch

Sea bass Yellow perch

Barramundi Salmon

Climbing perch Sturgeon

Jade perch Carp

Murray cod Eels

Goldfish Koi

Koi Crayfish

Freshwater prawn Freshwater mussels

Red claw crayfish

Yabbies

In the Aquaponics NOMA trials, the fish used were brown trout (Salmo trutta), rainbow

trout (Oncorhynchus mykiss), Nile tilapia (Oreochromic nilotica), Arctic char (Salvelinus

alpinus) and silver perch (Bidyanus bidyanus) (Skar, et al., 2015), with Nile tilapia and

Arctic char grown during the trial at Matorka.

It is important to understand the stocking rates and system capacity in a recirculating system,

because if there are too many fish and the plants and biofilter cannot treat the water

efficiently, then ammonia toxicity can result. For commercial systems, sequential rearing or

multiple rearing units might be required to keep the stock at the correct capacity in the tanks

(Rakocy, et al., 2008). Calculations are available in several of the aquaponics guidebooks

and online to work out stocking densities of fish, feeding rates, and optimum water volume:

grow bed ratios (typically around 1:4; Rakocy et al., 2008). Various factors influence these

parameters, such as plant species, growing system, water exchange rates etc. The hydroponic

component needs to be larger than the water volume, since a lot of nitrification and plants

are required to absorb the nutrients produced by the fish.

An important consideration with fish selection is about the diet preference of the species.

Many backyard aquaponics growers try to minimise costs by feeding the fish on non-

commercial fish feeds, and in some cases, on plants that are grown in the system itself, which

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is easier with omnivorous and herbivorous species. Tilapia are omnivorous, so this is one

reason why they are so popular as an aquaponics fish. Elsewhere, herbivorous species such

as grass carp have been trialled, since in some places (like Australia and New Zealand),

tilapia are banned (Lennard, 2010).

3.1.7 Fish feed

Fish feed is a controversial part of aquaculture. Currently, the easiest and most efficient feed

option is to use commercially available pellets, which are easily purchased, shipped, stored

and handled. The problem is that this feed contains fish protein – meal and oil made from

wild-caught fish, in proportions ranging from 20-30% (for shrimp feed) to 50% (rainbow

trout feed) or even up to 90% for black sea bass (Rust, et al., 2011).

Aquaponics can help solve some of the big problems with aquaculture if the system is

correctly designed. As discussed above, the plants are effectively a filter for the water after

the fish have lived in it, allowing the water to be reused repeatedly in a full or partially closed

cycle, and preventing the necessity for the release of excess nutrients into the environment.

However, the sustainability of the methodology is compromised if the aquaponics facility

has a huge environmental impact elsewhere. Additionally, some of the artisanal or small-

scale farms who may be experimenting with aquaponics are aiming for organic or non-GMO

certification for their products (Wilson, 2006). Therefore, moving away from wild-fish

sourced feed, and also from commercial feeds that may contain GMO grains, is a priority

for aquaponics.

Some promising alternatives to feeds made from wild fishmeal and oil are soy, barley

concentrates, high protein bacterial products made from food and brewery waste, and

importantly, insect protein (Nelson, 2010; Makkar, et al., 2014).

On a small scale, some in the aquaponics community use household compost to cultivate

Black Soldier Flies (BSF) to feed their fish. There are even dedicated BSF growth units that

can be purchased online. One of these, the BioPod Plus, explains in its manual that the BSF

grubs can be used for feeding wild birds, chickens, fish, pigs, reptiles and even humans,

although they do not advise it because of food safety concerns (Prota Culture, LLC, 2017).

Commercial scale production of insect protein is also becoming a reality with viable projects

reported in England (Fleming, 2016), South Africa (Byrne, 2017), and Europe

(PROteINSECT, 2016), where EU regulations now allow insect protein as an ingredient in

animal feeds (Fernandez, 2016).

One issue raised by Matorka and other aquaculture companies, is that replacing the feed

source must not compromise the nutritional quality of the product. This has been a concern

with alternative feeds since the omega oils in fatty fish come from their diet, and different

fish have different nutritional requirements. A new resource, the International Aquaculture

Feed Formulation Database, is being created by feed manufacturers to compile these

different nutritional needs, and to collaborate on finding alternatives to fishmeal and fish oil

(Orlowski, 2017).

3.1.8 Food safety

A working definition of a commercial-scale farm is that the farm is food safety certified

(Tokunaga, et al., 2015). Most small-scale farms, therefore, do not have to worry about food

safety regulations – aquaponics in most places is considered a type of gardening. Precautions

should be taken with all systems that produce food, however, such as maintaining hand-

washing practices, washing vegetables before eating, keeping rodents and other warm-

blooded animals away from the system, and wearing gloves to prevent cuts and scratches

that could become infected (Hollyer, et al., 2009).

For commercial operations, the food safety regulations in most places are based on

aquaculture and hydroponic food production guidelines, and so facilities could be inspected

to ensure adherence to the local laws. In the United States, for example, this could include

testing in the facility for pathogens, which should not exceed 126 Escherichia coli CFU/100

mL, nor 33 Enterococci CFU/100 mL (Hollyer, et al., 2009).

Good agricultural practices (GAPs) are advocated in aquaponics farming, to mitigate

pathogen risks for human health, but also for plant and fish health. GAPs are focused on

cleanliness, worker hygiene, keeping warm blooded animals (and their waste) out of the

system (this is the main way E. coli or Salmonella spp. might be introduced), and washing

products in fresh water before consumption (Somerville, et al., 2014).

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Various experiments have been conducted on plants to establish the ability of plants to take

up pathogens from the soil or water they are grown in. Hirneisen, et al., (2012) reviewed all

the important papers on the subject in 2012, which showed a lot of variability between results

based on species of plants, species of pathogens, conditions of plants, and growing

conditions, but it seems that especially in hydroponic growing methods, there is a real risk

of pathogens like E. coli and Salmonella sp. being taken up into the roots of the plants, and

possibly travelling to the edible tissue. So for a commercial aquaponics farm selling produce,

it would be essential to prevent contamination of the system water by bacteria, viruses and

parasites that could cause illness in humans.

Fish themselves are unlikely to emit common human pathogens in their waste, since they

are not warm-blooded (Sobsey, et al., 2006). The World Health Organisation lists

domesticated mammals and birds, as well as wild ruminants, as potential reservoirs of E.

coli (World Health Organisation, 2016). It is therefore necessary to stop birds, bats, reptiles

and amphibians (which have been linked to Salmonella; (World Health Organisation, 2016),

and domestic animals accessing the aquaponics system. Most contamination is transmitted

by workers, however, so GAPs and worker hygiene are still the most important issues

(Hollyer, et al., 2009).

In terms of contamination of the fish product by pathogens, there is not really a concern as

long as the fish is cooked (World Health Organisation, 2015). In fact, there is even a branch

of aquaculture research looking at growing fish in human wastewater ponds (Pescod, 1992),

which has found that aquaculture conducted in water containing up to 103-104 faecal

coliforms/ 100 mL is unlikely to cause accumulations of pathogens in fish muscle, although

at higher bacterial concentrations it could (World Health Organisation, 1989). In any case,

cooking of fish and aquatic plants grown in wastewater (even wastewater that contains

human faeces) is considered enough to destroy the common pathogens (Pescod, 1992).

3.1.9 Plants

Plant species

Virtually any herb, leafy green and vegetable can be grown in an aquaponics system, given

enough space and growing media (Lennard, 2010). Table 5 is taken from Bakhsh et al.

(2014), who list plant options described in the aquaponics and IMTA literature. In general,

aquaponics experts advise that leafy greens are more suitable for low-nutrient systems,

because they require less nutrition. Fruits are more successful in densely stocked or larger

systems.

Table 5. Plant candidates for FIMTA operations in temperate to cold regions (Table 3 in Bakhsh et al, 2014).

Vegetables

Artichokes Asparagus Beans

Beets Bok choi Broccoli

Brussels sprouts Cabbages Carrots

Cauliflowers Celery Collard greens

Cucumbers Eggplants Kale

Kohlrabi Leeks Lettuces

Mustard greens Onions Parsnips

Peas Potatoes Pumpkins

Radishes Rapini Rhubarb

Salicornia Spinach Squash

Swiss chard Tatsoi Yams

Fruits

Bananas Blackberries Blueberries

Cantaloupe Dwarf citrus trees Grapes

Lemons Pineapples Raspberries

Strawberries Tomatoes Watermelon

Herbs

Basil Chervil Chives

Cilantro Dill Fennel

Garlic Lemon balm Marjoram

Mints Oregano Parsley

Rosemary Sage Sorrel

Tarragon Wasabi Watercress

Ornamental plants

Calendula Carnations Coleus

Cosmos Dianthus Marigold

Pansy Petunia Roses

Snapdragon Sunflower Tulips

Yarrow Zinnia

Medicinal plants

Dandelions Echinacea Horse heal

Nasturtium St. Joh s wort Yarrow

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A big consideration when designing a commercial aquaponics system is the marketability of

the plants grown. If the plants cannot be transported easily and sold at a competitive price,

then they do not enhance the value of the aquaponics business. This is less of a problem in

small-scale aquaponics where households can experiment until they find suitable plants that

they can grow easily, care for well, and eat happily. In Northern Europe and Iceland, it has

been suggested that herbs would be an ideal selection since they fetch a relatively high price,

are space-efficient and fast growing and have a broad market appeal (Skar, et al., 2015).

As well as plants for human consumption, some facilities grow plants as part of the feed

requirements for the fish. Commonly these plants would be duckweed or Azolla sp., that the

fish could eat directly as a supplement to other feed (Somerville, et al., 2014). There are also

small-scale farmers who combine soil and aquaponic agriculture, occasionally also with

vermiculture, and use the inedible parts of plants to make compost for sale or for growing

insects (Punjabi, 2015).

Nutrient removal capabilities

Different plants have different capacities for nutrient uptake, and so different efficiencies in

an aquaponics system. These differences are related to different growth characteristics,

different nitrogen utilisation capacities and different root surface areas (affecting nitrifying

bacteria coatings) in different species (Hu, et al., 2015).

Four leafy vegetable species popular for markets in Vietnam were analysed to assess their

ideal hydroponic growing conditions and nutrient uptake capacity with a view to using them

as aquaculture waste water treatment plants (Trang, et al., 2010). The growth and

productivity of lettuce (Lactuca sativa L.), water spinach (Ipomoea aquatica Forssk.), pak

choi (Brassica rapa L. var. chinensis L.) and choy sum (Brassica rapa L. var. parachinensis

L.) were compared under different root flooding treatments (drained, half-flooded and

flooded), and it was discovered that the two Brassica varieties performed better in drained

root conditions, and L. sativa and I. aquatica grew best under the half-flooded and flooded

conditions. In another experiment, water spinach was significantly more efficient at

removing TAN, nitrite-N, nitrate-N and orthophosphate than mustard greens (Brassica

juncea) due to it having a more developed root structure and so more microbial attachment

sites (Enduta, et al., 2011).

Using a floating raft system and a high density of tilapia, Hu et al (2015) showed significant

differences in nutrient absorption between tomato (Lycopersicon esculentum) and pak choi

(Brassica campestris L. subsp. chinensis) aquaponics systems that were identical in every

other way. Because of a greater root surface area on which nitrifying bacteria could grow,

higher nitrogen use efficiencies were obtained in the tomato system than the pak choi system.

Lower TAN and NO3- concentrations were also observed in the tomato aquaponics system,

which improved the water quality and resulted in better fish growth.

The authors noted that for tomato plants, the high leaf surface meant that evapotranspiration

resulted in water additions to the fish tanks being required that negated the fresh water

conservation benefit that is often described for aquaponics (Hu et al, 2015). They also

showed that higher N2O emissions may be associated with higher TAN concentrations.

Algae

There are thousands of species of micro- and macroalgae, many of which could have useful

applications and good potential in aquaponics systems. There are species that grow in fresh,

brackish and saline water, so as with edible plants, the aquaponics grower needs to select the

species based on the dynamics of the particular system, and the market for products.

The usefulness of algae species is an important new branch of research, with potential

applications for mitigating climate change, improving food security, supporting renewable

energy and even reducing the use of petrochemical plastics. Both macroalgae and microalgae

species are proving to have exciting applications that could hasten the growing appeal of

saline and brackish aquaponics:

• Gourmet food with nutritional benefits such as high protein, high vitamin C, as much

Omega-3 as many fish, and several other minerals, some extractable for supplements

(GreenWave, n.d.; Schiffman, 2016).

• Macroalgae added to cattle feed reduces ruminant methane production (Machado, et

al., 2014). The authors experimented with 20 tropical macroalgal species including

three freshwater species, and showed that two species, the red algae Asparagopsis

and the brown algae Dictyota were the most effective at mitigating enteric CH4

emissions, although high doses might inhibit the anaerobic fermentation that cattle

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need to obtain optimum nutrition. The freshwater macroalgae trialled had a closer

nutritional composition to traditional plant feed, but were less effective at reducing

methane production.

• Microalgae as an addition to fish meal for aquaculture (Norambuena, et al., 2015).

• Algae as a biofuel. Some strains of algae produce higher amounts of oil per weight

than any other oilseed crop. Figures quoted, which make algal oil production seem

like a very good option include: Yields 60 times higher than soy beans and 5 times

that of oil palms per acre of land (Dunford, 2010), carbon dioxide emission savings,

new jobs and economic growth (Algix). Other authors are more cautious about the

potential, and say that microalgae ‘fuel only’ is not economically viable unless

innovative additional products are co-produced (Zhu, 2015).

• Biopolymers and bioplastics made from algae (oilgae, n.d.).

• Macroalgae as filters for chemicals, nutrients and carbon dioxide in waterways.

NOAA scientists have shown that if we can increase seaweed production worldwide

by 15% per year, by 2050 the plants would be able to remove 18% of the nitrogen,

61% of the phosphorus (both from fertiliser run-off in the oceans), and 6% of the

excess CO2 which the ocean has absorbed from human emissions (Goodyear, 2015).

When growing microalgae, it can be difficult to avoid contamination with competitive

organism such as phytoplankton, phytophagous zooplankton and bacteria, so care has to be

taken with the culture medium, the air supply, the starter culture, and the infrastructure used

as tanks (Dunford, 2010). Dunford (2010) advises that the most efficient and trouble-free

way to grow a monoculture of a single species is in a photobioreactor, which might make

commercial-scale microalgae production in aquaponics more expensive and complicated

than it is worth. In any case, microalgae culturing would require still volumes of water, not

flowing systems (as aquaponics traditionally uses), so it is difficult to envisage a

recirculating system. A simple method of utilising aquaculture wastewater to grow

microalgae before releasing it to the environment would require experimentation to establish

the correct frequency of water exchange, culture time, and prevention of unintended growth

of contaminants.

Macroalgae production is a big industry (mostly in Asia) – nearly half of the world’s ocean-

farmed products are marine macroalgaes (Goodyear, 2015), so the technology and research

already exists, as well as markets for products in some parts of the world

In summary, plant choice in a particular aquaponics system depends upon the intended use

of the plants (for home consumption, fish feed, or the target market for products), and the

technicalities of the system (fresh, saline, low- or high- nutrient). Micro- and macroalgae

production is an important new area for research and experimentation.

3.1.10 Pests

One of the difficulties that aquaponics users report is that pests and diseases can be difficult

to treat. Pest infection in Hawaiian aquaponics lettuce farms has caused the loss of entire

crops on multiple occasions (Tokunaga, et al., 2015). Catastrophic crop loss can lead to the

loss of vendors and other disruptions to the business.

The principle of aquaponics is that it is chemical free, since the plants or fish could react

badly to chemicals introduced to one or other part of the system. This means that treatments

for common plant pests cannot be used, and varieties of the sustainable agriculture technique

called Integrated Pest Management (IPM) must be used instead (Bittsanszky, et al., 2016).

IPM could include biological control (e.g. resistant cultivars, predators), physical barriers,

crop rotation to deplete habituated insects (Somerville, et al., 2014), traps, and manipulation

of the physical environment to reduce heat, humidity and plant overcrowding (Somerville,

et al., 2014; Rakocy et al., 2008).

Bittsanszky et al (2016) describe experiments conducted in their commercial-scale

aquaponics system in Hungary, where they used ‘beneficial organisms’ as a first, low risk,

step to treat any issues with plants as they arose. The three biocontrols mentioned by these

authors for control of pests on their tomato plants were:

• Encarsia formosa against white fly. This tiny wasp is a parasite of the common

greenhouse pest, white fly, which can be ordered from suppliers (Planet Natural

Research Centre, 2004-2016).

• Ichneumons against aphids. The Ichneumonoidea are a parasitic wasp family. The

Bittsanszky et al. (2016) paper does not specify which species were used.

• Phytoseiulus against spider mites. Probably Phytoseiulus persimilis, a carnivorous

mite that preys on spider mites and is encouraged as a biological control (Planet

Natural Research Centre, 2004-2016).

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The authors also noted the importance of sanitation measures in the aquaponics facility, as

soil-borne infections from outside the system can be prevented by good hygiene. They used

hand and foot washes, and disinfected clothing, hardware and other external materials before

they were brought in. The plant propagation step was also analysed for potential sources of

infection.

When chemicals are required, natural chemicals are available which have had their toxicity

tested on fish. Then, by following label instructions, minimising chemical contact with the

water (e.g. wiping chemical directly onto plant fungus) and keeping a careful log of the

impacts on the fish, it is possible to utilise some commercial pest treatments (Pilinszky, et

al., 2015).

The lack of chemical pest control is one of the selling points of aquaponics, and a marker in

the science of agroecology (as opposed to industrial agriculture). Using no chemicals allows

some aquaponics farms to work towards organic certification (although there is sometimes

an issue with where the fish feed is sourced from), and allows aquaponics to avoid the human

health and environmental impacts that non-organic soil farms and most aquaculture facilities

contribute to (United Nations Human Rights Council, 2017).

3.1.11 Energy

Summarising the literature, there are four reasons that aquaponics developers have

concentrated on energy sources in their research:

• Because the aerators and recirculating water pumps must always be ‘on’ in an

aquaponics system, a constant energy supply is required, possibly with automatic

backup generators if the system is commercial grade (Rakocy, et al., 2008). As with

a commercial aquaculture facility, a power loss can mean a catastrophic drop in

oxygen levels and fish death (Sveinbjörn Oddsson, personal communication,

September 2012).

• To reduce the costs of a commercial operation, many farms install renewable energy

technology, reduce their reliance on grid electricity, and thereby reduce their

operational costs. In the economic analysis of Hawaiian aquaponics farms, it was

shown that a solar photovoltaic system pays for itself in 8-9 years, without even

receiving any government incentives (Tokunaga, et al., 2015).

• Another energy-related issue in aquaponics is the desire for many backyard

aquaponics enthusiasts to be off-grid or self-sufficient, and potentially, for

commercial systems to be carbon-neutral and so not rely on energy produced by

fossil fuels.

• Aquaponics is an ideal food-production method for rural, developing and isolated

communities, where constant power supply may not be an option (Somerville, et al.,

2014).

For these reasons, self-sufficient systems that generate their own power have been designed.

One such research project was by Julia Gigliona for a research degree in Sweden (Gigliona,

2015). Gigliona designed an aquaponics system with a biogas digester to produce methane.

The methane can be used in a Combined Heat and Power Plant (CHP), for production of

heat and energy to be used by the aquaponics system (particularly useful in Northern

climates), or for household heating and cooking. This energy loop had the benefit of reducing

waste from the system (compostable non-edible plant parts and solid fish waste), and

reduced energy inputs (heat and electricity). Gigliona (2015) calculated the optimal size of

the system to generate enough fermentable waste to produce enough methane for the energy

requirements. She concluded that a large aquaponics system would be required to generate

enough methane to keep a CHP running (1000 m3 of water, 50 t of fish, 800-900 m2 grow

beds). In Sweden, where the test case was based, the electricity available to be bought would

be cheaper than the cost of building the digester and buying a CHP. However, if electricity

was not cheaply available (such as in a more expensive country, or in a developing country),

then it could become cost effective. Additionally, if electricity requirements could be met by

solar and no heating was required (in the tropics, for example), then the methane from the

biogas digester could be used to generate household or system electricity.

Another engineering team from a university in the United States designed a similar CHP

system for environmental conditions in Milwaukee (Chapman, et al., 2012). They also

designed software to calculate the greenhouse gas emissions saved by using various types of

generator systems, some which save energy by cogenerating heat with power, although none

used biogas. The research shows that such systems are theoretically possible, and all the

technical calculations are explained in great detail, allowing others to try out the designs

(Chapman, et al., 2012).

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With the advent of smaller, cheaper, and more efficient batteries and solar panels, electricity

self-sufficiency is becoming a feasible proposition for many people in poor, rural and

developing locations (Lewis, 2017). Combined with a global trend towards agroecology

(United Nations Human Rights Council, 2017) and a push for local food production to work

towards international sustainable development goals (discussed in Chapter 4.6), aquaponics

is set for a surge in opportunities and advocates.

3.1.12 Technology

Renewable energy is only one technological innovation that is changing agriculture and

aquaculture. A list of innovative ‘ag-tech’ has been compiled by CB Insights (2017), who

looked at startups promoting technologies that increase the efficiency of farms, sensors,

aerial-based data, internet distribution, and tools for technology-enabled farming. Some of

this new technology relevant to aquaponics gives a flavour of how the industry might

develop (CB Insights, 2017):

• Farm management software and ‘predictive analytics’ that allows farmers to

efficiently manage their inputs, production and processes. This includes software

aimed at making breeding and genetic information more accessible and useful.

• Sensors to collect data to monitor crop and animal health, or system parameters.

• Robotics and drones for automating farm functions.

• Smart irrigation, which could be applied to some aquaponics systems that deliver

water at intervals.

• New e-commerce opportunities connecting farmers directly to suppliers and

consumers.

Elsewhere online, marketplaces for buying aquaponics equipment and kits have been around

for a long time, and online communities are quick to assess new products and developments

to ensure they are utilised where they are helpful. For example, every aquaponics forum and

website has discussions and articles about lighting, and comparing LED lighting with every

other kind of grow lamp. Here is one piece of advice as an illustration of the way technology

is integrated into aquaponics:

“I’ve been pretty sceptical about LED fixtures because of what I’ve heard and read in industry literature. The common thinking was that, while LEDs have

tremendous potential for the future because the bulbs never need to be replaced

they just don’t grow plants well enough yet to justify the high prices. My tune

has changed completely since the ‘discovery’ of Black Dog LED fixtures. I’m convinced that these fixtures are the best on the market today, and I’ve seen some amazing growing results with my own eyes (Black Dog headquarters is

conveniently located about ten minutes away from my home). Plus they offer a

lifetime warranty. I now believe the days of LED growing have arrived” (Sawyer, 2013).

There are similar examples regarding every facet of aquaponics. Usually information is

aimed at the small-scale farmer, but because the industry leaders in aquaponics are skimming

from hydroponics and aquaculture research, and because specialist aquaponics e-

marketplaces are competitive (and want to sell high end products) there is plenty of

commercial-scale-relevant information available too.

As well as technology influencing aquaponics, it has been suggested that aquaponics can

also be a source of innovation. Researchers who analysed 73 ‘ZFarms’ (zero acreage farms)

around the world showed that urban farming, including aquaponics, can function as an

innovation incubator (Thomaier, et al., 2014). The initiative to move into previously

unfarmed space, or to farm new species, can enable technological innovation to solve new

problems and engage new audiences, for example solving bioclimatic design issues by

creating living walls that help cool a city, utilise waste, provide green space and also function

as food production (Eaton, 2013). New concepts of food production, sustainable ways of

organising urban life, and novel consumption initiatives are potential outputs of aquaponics

and similar farming systems (Thomaier, et al., 2014).

3.1.13 Advice, guidance, and the internet

The internet is the home of information about improving the sustainability of one’s life.

There are real-life books, journals, and courses that cover some of the same information, but

for many reasons, information is more accessible, more current, more diverse, and more

critiqued on the internet. There are at least 9 active aquaponics forums which in 2012, were

estimated to have over 5000 participants each (The Aquaponics Doctors, 2012), and over

200 Facebook pages and 100 groups that deal with aquaponics (www.facebook.com;

accessed April 1, 2017). Many more focus on related pursuits of urban farming, hydroponics

and permaculture. A small community survey was conducted to understand more about how

the aquaponics community interacts with online advice. The results are presented in the next

section.

75

3.2 Survey results

There were 47 responses to the survey, of which 37 were considered ‘complete’ by the

Survey Monkey software. Ten respondents skipped one or more question.

A summary of the survey responses is presented below, and the complete survey responses

are included in Appendix B.

Eighteen respondents were from the USA, 3 from Canada, 6 from Australia, 2 from Europe

and 2 from South or Central America. Of these, 41% live in suburban areas, and 33% live

on a rural property. Smaller numbers said they live in an urban area. Most of the responders

had another job or were retired, although 30% (14 responders) said aquaponics was their

main business.

The survey respondents all had different levels of interaction with the online community,

and were at different stages of their aquaponics experiments. Table 6 shows their level of

participation.

Table 6. Responses to Question 1 of the community survey - community participation.

Q1. What is your level of participation in the online aquaponics community? (Please choose all

the answers you agree with)

Percentage Number

I am new to the community 14.89% 7

I have been participating in the community for a few weeks 2.13% 1

I have been participating in the community for a few months 27.66% 13

I have been around for years 42.55% 20

I visit forums, read online information and watch videos 68.09% 32

I ask questions on forums and get advice from others 42.55% 20

I answer others' questions and participate in discussions 53.19% 25

I blog and/or make videos about my aquaponics experiences 19.15% 9

I run a forum and/or people seek me out for advice 17.02% 8

Those who responded mostly had a medium sized garden, produced vegetables for home

consumption, and were interested in self-sufficiency (Table 7).

Table 7. Responses to Question 4 of the community survey - garden details.

Q4. What is your garden like? (Select as many as you like)

Percentage Number

Small - balcony or inside house 6.52% 3

Medium - urban garden or roof-top 45.65% 21

Large - big garden or rural property 30.43% 14

Commercial - I can make money out of this thing 19.57% 9

I (plan to) eat the fish regularly 41.30% 19

The fish are only to provide nutrients 21.74% 10

I (plan to) eat the fish occasionally 32.61% 15

I get a steady supply of veggies for myself and my family 54.35% 25

I occasionally eat fresh produce from my garden 15.22% 7

I sell or swap veggies because I have plenty 17.39% 8

Aquaponics is my main business 30.43% 14

I am (trying to be/mostly) self-sufficient 54.35% 25

The participants were all positive about aquaponics, with 70% of respondents relating their

participation to environmental sustainability, over 50% seeing it as a hobby, 30% believing

it could be a coastal management tool, and 75% agreeing that it has potential for improving

food security in developing countries (Table 8).

Table 8. Responses to Question 9 of the community survey - aquaponics in a world context.

Q9. Please select all the responses that you agree with, and add any other statements that

describe how you feel about aquaponic gardening:

Percentage Number

Aquaponics is a lot of work for not much reward 12.20% 5

I consider aquaponics to be an expensive hobby 14.63% 6

I tried aquaponics but it doesn't really work for me 0.00% 0

Aquaponics works out to be cost effective for me and my family 41.46% 17

I could make money out of running an aquaponics business 51.22% 21

I participate in aquaponics because I like to grow my own food 85.37% 35

I participate in aquaponics because I am passionate about environmental sustainability

70.73% 29

I participate in aquaponics as a hobby 56.10% 23

I would like to see a stronger aquaponics community in my area 73.17% 30

I can apply for grants in my community to help me start up an aquaponics farm or business

21.95% 9

The government in my area should consider providing more funding/assistance for aquaponics

48.78% 20

I think cities should consider aquaponic farming to improve their sustainability or to deal with waste

70.73% 29

77

Aquaponics has a lot of potential for improving food security in developing countries

75.61% 31

Aquaponics is an important tool for improving the way coastal resources are managed

31.71% 13

I am worried about environmental issues (such as...) and I see aquaponics as a potential solution

65.85% 27

I take part in other environmental activities or sustainability initiatives

60.98% 25

I mostly follow others' instructions for aquaponics 17.07% 7

I experiment a little bit and adapt my design to my space/community

51.22% 21

I am really into design and innovation in aquaponics 60.98% 25

Tables 9 and 10 present the answers to questions about the positive and negative aspects of

aquaponics. These responses were incorporated into the discussion of aquaponics strengths,

weaknesses, opportunities and threats in Chapter 4.

Table 9. Responses to Question 7 of the community survey - positive aspects of aquaponics.

Q7. Why are you involved in aquaponics? What are the positive aspects of your experience?

[Spelling and grammar lightly edited for clarity.]

Interesting in a more sustainable way of doing

things - especially low water use. Just learning

I plan to build a commercial system in the near

future.

Involved because I want to know exactly what I am

putting in my body. I can grow off season produce in

my greenhouse. Gardening has always been

something I wanted to do

I don't have good soil which led me to hydroponics

then aquaponics. I love fish and plants and it just

seemed really cool. I love spending time at the

garden and feeding the fish.

I do it and aquaculture commercially for a living To learn food production with minimal water

requirement .

Hobby trying to turn into a business Because it's my job. Too many to list

Looking to end reliance on commercial food

supplies

grow food

Stumbled across it about a 1.5 yrs ago and it

resonated with me so I convinced my partner that

we should try and see what happens

Have been working with a nonprofit organization.

They received a grant and with my interest the

project fell to me.

Fresh vegies and fish that you know what has been

applied to them right up to your table. Food safety.

Out of interest with a view to building experience

and setting up as a not for profit community

business. Possibly, ultimately as a commercial

concern.

Think it might be future in food production No

weeds

I am seeking self-sufficiency. I like that faster

growth rates

To grow organic vegetables, keep the fish as a fun

hobby and teach others to do the same; food

security and a living if possible.

To promote Hawaii's aquaculture industry.

Aquaponics uses much less water and plants grow

faster

To make money. cutting propagation, learning

Supplements my organic farming. Longer/faster

growing season.

Research Outdoors in sub tropics Indoors in

temperate climates

Fun, learning, experimenting, growing veggies it's been fun learning

I am ADD and for over 60 years. My green house is

attached to my wood working station. We have

fresh pies, new sauces especially elderberry. I get to

work inside on crappy days and outside on nice days.

I can do my own thing but have science back it up. I

want to make the system work and take it to

Guatemala.

I believe it is the future of urban agriculture. Most

of our food is imported. People have forgotten how

to grow their own food. If our food supply is

interrupted chaos will reign. High school students

are beginning to show more interest in my

operations. I believe that aquaponics is the solution

to our food, energy, land, and water crisis.

Better growing environment, Teaching and

education people all we can about this aquaponics.

I feel aquaponics is full circle in feeding people and

eating very healthy

Because is a safe way to produce high quality food.

Is the learning and teaching of a self sustainable

food production.

Improving agriculture means healthier food for

healthier people thus less sickness and imminent

reduction of child obesity!

Trying to scale up to commercial production. I am

an advocate for the many positive environmental

aspects of aquaponics.

Interested in sustainability. Good feeling of

community, worth it to grow locally produced

organic food with no packaging

passion for restoring natural habitats waterways

spawning creeks etc

Interesting in a more sustainable way of doing

things - especially low water use. Just learning

Self sufficiency My hobby

Table 10. Responses to Question 8 of the community survey - negative aspects of aquaponics.

Q8. Are there any negative aspects to your aquaponics experiences? (Online or in your garden).

[Spelling and grammar lightly edited for clarity.]

Yes, I had a lad do ate so e fish fo p oje t and I ended up killing most of them. Apparently I

used some water that came off roof (rainwater).

But, I had forgotten that I had sprayed insect spray

i it to kill the os uitoes.

It is ha d o k ut a e a di g o e. E e he ou study aquaponic materials and you become the

smartass that thinks that you are the student that is

smarter than the teacher then you create new ways

of doing things and you kill all your fish when you

make adjustments to improve your system but you

disturb it instead and all your fish turn belly up.

Nature also discourages you at times during storms

or other type of natural disasters or drastic weather

changes. Perseverance makes a difference between

failu e a d su ess. Sta t s all a d g o ig late !

It is ot as eas as people sa . Ma people a e i it to make money, not to help society. Industry is in

it's infancy. Not much scientific data out there on

aquaponics, so there is a lot of hearsay and

u su sta tiated opi io s.

You get addi ted lol. Whe t i g to e plai e a tl what aquaponics is you always have to mention

hydroponics as a point of reference. and then people

assume you’re growing marijuana. Convincing them

othe ise is al ost i possi le.

The o l eal egati e I ha e see is if ou do ha e problems with insects you can't do much about it

because you can't use pesticides, etc. around

a uapo i s.

I t ul e jo e e pa t of it Loss of fish due to sill istakes

o heati g a d pa t ost

Lea i g u e. False a d isleadi g i fo atio o li e

Mistakes a e ostl he u i g pa ts/pie es. So many different answers on-line, sometimes the

ad i e is 't al a s a u ate!

So a ays to configure the system. Hard to

figure out the best way for our setup. Feel like I have

to be an expert in so many areas (fish, plants,

h d opo i s, plu i g, et .)

Ti e take fo s ste to atu e No

No e et spa e, a d I a t a la ge s ste

Too u h i fo atio , too a optio s/ a ia le, ha d to k o he e to sta t. E pe si e i itial osts.

I see a people t i g to make big money in

selli g a uapo i s ste s a d e e did it.

Sta t up is a little ostl ostl fo the g ee house.

Hard to find complete knowledge bases. I've had to

pie e the i fo togethe .

Ma folks gi i g ad ad i e that has ot ee proven. Lack of trained professionals to run

s ste s.

79

I feel te i le he fish die. I should ha e brought them all into the garage but I never thought

the $10,000 heating system would fail. I am looking

into the German Sunlight heating system for water

ut I a t to eti e efo e I pu hase it.

Yes, he e sta ted uildi g a uapo i s, so e of the components have lead us ways to make and

upgrade certain components. Do find the best way

fo a good fu tio i ou a uapo i s s ste .

Yeah, fish die a d pla ts die too. It’s just a part of

ga de i g.

ti e is 't al a s a aila le to do as u h o k as I’d like

Deali g ith outdoo eathe e t e es Nut ie t defi ie

No It a e diffi ult to e ost effe ti e

I egio , the la k of materials and involved

people.

Maki g o e o a la ge o e ial s ale is a challenge in the USA so far because of the price of

o e tio all p odu ed food.

ot eall NO

o l thi gs I eed to lea ho to o t ol, eg aphids, la k of i o et

Bugs

3.3 Matorka aquaponics trial results

As shown in Table 1 (page 41), this section uses abbreviations for the experiment variables:

‘T’, ‘N’, ‘U’, and ‘B’ refer to the tap, nutrient rich, unfiltered, and biofiltered water sources

used in the four different treatments, while ‘P’, ‘H’, ‘R’, and ‘A’, stand for pumice,

Hydroton, raft, and algae, the four different growth media. Therefore, the acronym ‘TP’

stands for the tap water treatment, with pumice as the growth media, etc.

All results are shown in Appendix C.

3.3.1 Plant growth characteristics

Plant growth was monitored with a series of photographs of each experiment box. These are

all available in Appendix C, but as an example, Figure 14 shows the photograph series for

the ‘biofiltered, raft’ experiment box.

Figure 14. Example of the photo series for each experiment box to monitor plant growth during the experiment.

The photograph series allowed observation of how the experiment was working, and any

issues. The two photographs in Figure 15, for example, demonstrate the growth of algae (or

possibly an algal-bacteria complex) on the growth media, especially on the ‘unfiltered’

pumice and Hydroton, but also on the ‘biofiltered’ treatments to a lesser extent.

81

Figure 15. Hydroton and pumice experiment boxes showing the development of algal mats in the growth media. The column on the left is the Hydroton boxes and the column on the right is the pumice boxes. From bottom to top, the treatments shown (rows) are ‘tap water control’, ‘unfiltered’, ‘biofiltered’, and then ‘nutrient control’ at the top/back. Extensive algal growth can be seen in the two unfiltered boxes (red circles). It also grew in the raft box, and in the biofiltered boxes, to a lesser extent.

Graphs showing the changes in plant growth measurements between Day 0 of the experiment

(22 Oct 2012) and Day 28 (19 Nov 2012), are presented in Figures 16 to 18. They are

presented as ‘percentage change’ as discussed in the methods, to illustrate only changes

related to the experiment treatments, not natural variability between plant types.

Table 11 shows the p-values of the t-Tests administered on some of the same ‘percentage

change’ results, to see whether the experimental treatment results were significantly different

from each other. An asterisk indicates significance. The significantly different data are

mentioned in the explanation of the results, below.

Table 11. p-values for paired t-Tests performed on experimental data. An asterisk indicates significance.

The plants in the three ‘tap water control’ experiment boxes (TH, TP and TR), showed a

lower percentage change in all the growth measurements, including Total Plant Length

(Figure 16), Total Leaf Area (Figure 17), and Total Dry Mass (Figure 18). The ‘unfiltered’,

‘biofiltered’, and ‘nutrient control’ treatments did not show significant differences between

the data for any of the plant growth characteristics.

In the Total Plant Length chart (Figure 16), the combined ‘biofiltered’ results were

significantly different from the ‘tap water’ control results (p=0.007), as were the ‘nutrient

control’ results (p=0.013). The plants in the ‘biofiltered’, ‘unfiltered’ and ‘nutrient control’

boxes did not show significant differences from each other for the parameter of change in

plant length. When the treatments were analysed for differences between growth media types

(pumice, Hydroton, raft), no significant differences were found.

Change in Plant Length

v Unfiltered Biofiltered Nutrient v Pumice Raft

Tap 0.066 0.007* 0.013* Hydroton 0.262 0.857

Unfiltered - 0.262 0.608 Pumice - 0.248

Biofiltered - - 0.467

Change in Total Leaf Area


Tap 0.000* 0.000* 0.000* Hydroton 0.123 0.109

Unfiltered - 0.104 0.198 Pumice - 0.927


Change in Total Dry Mass


Tap 0.002* 0.000* 0.000* Hydroton 0.031* 0.443

Unfiltered - 0.688 0.939 Pumice - 0.028*


83

Figure 16. Percentage change in Total Plant Length for the different plant types and experimental treatments. The percentage change in plant length in each of the 12 experiment treatments is shown. Error bars show the effect of the data range (four replicates for each data point) on the percentage change calculation for each plant type. Treatments: Tap water, Hydroton (TP); Tap water, pumice (TP); Tap water, raft (TR); Unfiltered, Hydroton (UH); Unfiltered, pumice (UP); Unfiltered, raft (UR); Biofiltered, Hydroton (BR); Biofiltered, pumice (BP); Biofiltered, raft (BR); Nutrient, Hydroton (NH); Nutrient, pumice (NP); Nutrient, raft (NR).

In the Change in Total Leaf Area chart, (Figure 17), significant differences were seen

between each of the nutrient-rich experiment data-sets (‘biofiltered’, ‘unfiltered’, and

‘nutrient control’) and the ‘tap water’ control data sets (p-values all < 0.001). The plants in

the ‘biofiltered’, ‘unfiltered’, and ‘nutrient control’ treatments did not have changes in total

leaf area significantly different from each other. Similarly, none of the three growth media

types were significantly different from each other for this plant growth parameter.

For the Change in Total Dry Mass parameter (Figure 18), the plants in the ‘tap water’ control

experiments showed significantly different growth to those in the ‘unfiltered’ boxes (p =

0.002), as well as to those in the ‘biofiltered’ boxes (p < 0.001), and those in the ‘nutrient

control’ boxes (p < 0.001). Between these three data sets, however, there were no significant

differences. When the Change in Total Dry Mass data were split into ‘growth media’ data

sets, significant differences were observed between the pumice and Hydroton treatments (p

= 0.031), and the pumice and raft treatments (p = 0.028), but not between the raft and

Hydroton treatments.

0

50

100

150

200

250

300

TH TP TR UH UP UR BH BP BR NH NP NR

Pe

rce

nta

ge

ch

an

ge

Plant Length

Basil

Lettuce

Rocket

Mixed

Figure 17. Percentage change in the Total Leaf Area measurements from the start to the end of the experiment, shown for the 12 different treatments (columns) and the three different plant types (series). The error bars are shown as percentages (Basil = 20%, Lettuce = 29%, Rocket = 37%), to reflect the effect of the percentage change calculation on the range of data from the four replicates that make up each data point. Treatments: Tap water, Hydroton (TP); Tap water, pumice (TP); Tap water, raft (TR); Unfiltered, Hydroton (UH); Unfiltered, pumice (UP); Unfiltered, raft (UR); Biofiltered, Hydroton (BR); Biofiltered, pumice (BP); Biofiltered, raft (BR); Nutrient, Hydroton (NH); Nutrient, pumice (NP); Nutrient, raft (NR).

Figure 18. Percentage change in the Total Dry Mass measurements from the start to the end of the experiment, shown for the 12 different treatments (columns) and the three different plant types (series). Treatments: Tap water, Hydroton (TP); Tap water, pumice (TP); Tap water, raft (TR); Unfiltered, Hydroton (UH); Unfiltered, pumice (UP); Unfiltered, raft (UR); Biofiltered, Hydroton (BR); Biofiltered, pumice (BP); Biofiltered, raft (BR); Nutrient, Hydroton (NH); Nutrient, pumice (NP); Nutrient, raft (NR).

0

500

1000

1500

2000

2500

3000

3500


Pe

rce

nta

ge

ch

an

ge

Total Leaf Area

Basil

Lettuce

Rocket

Mixed

0

500

1000

1500

2000

2500

3000

3500


Pe

rce

nta

ge

ch

an

ge

Total Dry Mass

Basil

Lettuce

Rocket

Mixed

85

Figure 19 summarises the differences between each of the growth media types, for the three

plant growth characteristics. As Table 11 shows, he differences observed between the

Hydroton and pumice, and the pumice and raft media were only significant at the 95%

confidence interval for the Change in Total Dry Mass parameter.

Figure 19. Data for all three of Total Leaf Area, Total Dry Mass, and Plant Length combined to show differences between media types.

3.3.2 Nutrient and water analysis

The results of the weekly water analyses are presented in Tables 12 and 13, and Figures 20

to 26. Table 12 presents results from analysis of water from different points around the

Matorka facility. All results are included in Appendix C.

0

20

40

60

80

100

120

0

200

400

600

800

1000

1200

1400

Hydroton Pumice Raft

Pe

rce

nta

ge

ch

an

ge

(P

lan

t le

ng

th)

Pe

rce

nta

ge

ch

an

ge

Media Comparison

Total Leaf Area

Total Dry Mass

Plant Length

Table 12. Results of weekly water quality measurements on water from various locations around Matorka. Orange and blue highlighted rows are referred to in the text. Red text results are questionable. The numbers beside the sample names refer to the sampling locations in Figure 3, page 36.

Date:

25-

Sep 1-Oct 11-Oct 22-Oct 29-Oct 3-Nov 11-Nov 19-Nov

Exp. Day: D-27 D-21 D-11 D0 D7 D12 D20 D28 Average n

NO3

mg/L

1. Cold Spring Water 0.12 0.20 0.16 2

2. Hot Ground Water 6.91 0.06 0.06 1

25 Degree tap mix 0.25 0.25 1

3. After char tanks 1.14 0.28 0.20 0.24 2

4. Outside, before raceway 1.65 0.19 0.19 1

5. Biofilter end 0.20 0.40 0.48 0.82 0.48 4

Biofilter end after aeration 0.64 0.64 1

6. Pump tank (unfiltered) 1.29 0.04 0.34 0.25 0.52 0.36 0.48 0.47 7

7. Matorka effluent to river 0.26 0.21 0.23 2

8. River water upstream 0.18 0.18 1

9. River water downstream 0.20 0.20 1

NO2

mg/L


2. Hot Ground Water 0.015 0.002 0.008 2

25 Degree tap mix 0.000 0.000 1

3. After char tanks 0.011 0.004 0.002 0.006 3


5. Biofilter end 0.057 0.042 0.050 0.111 0.065 4






PO4

mg/L


2. Hot Ground Water -0.02 0.09 0.09 1

25 Degree tap mix -0.03 -0.03 1

3. After char tanks 0.01 0.15 0.13 0.01 3


5. Biofilter end 0.05 0.13 0.04 0.25 0.12 4






TAN

mg/L

1. Cold Spring Water -0.08 -0.10 -0.09 2

2. Hot Ground Water -0.05 -0.10 -0.07 2

25 Degree tap mix -0.08 -0.08 1

3. After char tanks 0.09 0.04 -0.09 0.01 3

4. Outside, before raceway 0.12 -0.09 0.01 2

5. Biofilter end 0.18 0.36 -0.09 -0.09 0.09 4

Biofilter end after aeration -0.09 -0.09 1

6. Pump tank (unfiltered) 0.27 0.33 0.13 0.08 -0.09 -0.08 0.11 6

7. Matorka effluent to river 0.31 -0.09 0.11 2

8. River water upstream -0.10 -0.10 1 9. River water downstream x

-0.09

-0.09 1

87

The orange highlighted rows in Table 12 are important because these results help inform the

understanding of the nitrification process, and the performance of the biofilter. They are

measurements made on the water at the end of the biofilter (i.e. ‘biofiltered effluent’), and

the water from the pump tank, from which the experiment water was sourced (i.e. ‘unfiltered

effluent’). For nitrate and nitrite, the end of the biofilter had the highest concentrations out

of the locations measured around the facility. For phosphate, the highest average

concentration was in the unfiltered effluent in the pump tank. While most of the TAN results

are below the limits of detection of the technique, some measurements from the pump tank

and the effluent flowing to the river were acceptable and the highest measured around the

facility. Another point to notice in Table 12 is that the pH at the end of the biofilter was

lower than the pH in the pump tank every time they were both measured. This will be referred

to again in the discussion.

Table 13 shows the results of the regression analysis on all the weekly results. It shows all

the r2 statistics and p-values from the regression models calculated with Excel. Significant

results (i.e., where the change over time is not random) are marked with an asterisk. The

‘biofiltered effluent’ and ‘unfiltered effluent’ results from Table 12 were included in the

regression analysis. Other results are for nutrient and water quality measurements made on

samples from the experiment boxes. All results can be examined in Appendix C.

pH


2. Hot Ground Water 9.91 9.91 1

25 Degree tap mix 9.50 9.38 9.44 2

3. After char tanks 8.01 8.27 8.14 2


5. Biofilter end 8.43 7.62 8.78 7.38 7.58 7.82 7.94 6



8. Matorka effluent to river 8.67 8.67 1


TSS

mg/L

1. Cold Spring Water 0.0 0.0 1

2. Hot Ground Water 0.0 0.0 1

25 Degree tap mix 0.0 0.0 1

3. After char tanks 0.3 0.0 0.8 0.4 3


5. Biofilter end 0.0 0.0 1.2 1.6 0.7 4






Table 13. Results of regression analysis on each set of weekly samples. Where p < 0.005, an asterisk indicates a significant linear trend. Treatments: Tap water, Hydroton (TP); Tap water, pumice (TP); Tap water, raft (TR); Unfiltered, Hydroton (UH); Unfiltered, pumice (UP); Unfiltered, raft (UR); Biofiltered, Hydroton (BR); Biofiltered, pumice (BP); Biofiltered, raft (BR); Nutrient, Hydroton (NH); Nutrient, pumice (NP); Nutrient, raft (NR).

Analyte Experiment

treatment n

R

square P-value Analyte

Experiment

treatment n

R

square P-value

NO3

BP 7 0.904 0.001*

pH

BP 6 0.206 0.366

BH 7 0.919 0.001* BH 6 0.252 0.311

BR 5 0.650 0.100 BR 6 0.146 0.455

UP 7 0.950 0.000* UP 6 0.288 0.272

UH 7 0.961 0.000* UH 6 0.327 0.236

UR 5 0.268 0.372 UR 6 0.252 0.310

Biofilter effluent 4 0.918 0.042* Biofilter effluent 6 0.186 0.394

Unfiltered effluent 5 0.528 0.165 Unfiltered effluent 7 0.135 0.417

NO2

BP 8 0.137 0.366 TSS

BP 8 0.002 0.907

BH 8 0.428 0.078 BH 8 0.012 0.800

BR 5 0.824 0.033*

UP 8 0.524 0.042*

UH 8 0.522 0.043*

UR 5 0.783 0.046*

Biofilter effluent 4 0.407 0.362

Unfiltered effluent 7 0.048 0.637

PO4

BP 8 0.556 0.034*

BH 8 0.765 0.004*

BR 5 0.457 0.210

UP 8 0.836 0.001*

UH 8 0.455 0.067

UR 5 0.584 0.132


Unfiltered effluent 7 0.037 0.678

TAN

BP 8 0.502 0.049*

BH 8 0.485 0.055

BR 5 0.357 0.287

UP 8 0.386 0.100

UH 8 0.503 0.049*

UR 5 0.434 0.226


Unfiltered effluent 7 0.627 0.034*

For the charts in the following figures, the same abbreviations as in the last section are used.

When a trend in the data is significant, the linear trendline has been added, and the r2 value

given. Error bars were generated by assessing the precision of the analytical technique, as

described in the methods section, 2.3.2.

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Figure 22. Nitrate results for weekly water tests from the three 'biofiltered' and three 'unfiltered' boxes. Treatments: Unfiltered, Hydroton (UH); Unfiltered, pumice (UP); Unfiltered, raft (UR); Biofiltered, Hydroton (BR); Biofiltered, pumice (BP); Biofiltered, raft (BR).

Figure 21. Nitrate results for weekly water tests from the three 'tap water' and three 'nutrient control' boxes. Treatments: Tap water, Hydroton (TP); Tap water, pumice (TP); Tap water, raft (TR); Nutrient, Hydroton (NH); Nutrient, pumice (NP); Nutrient, raft (NR).

Figure 20. Nitrite results for weekly water tests from the three 'biofiltered' and three 'unfiltered' boxes. Treatments: Unfiltered, Hydroton (UH); Unfiltered, pumice (UP); Unfiltered, raft (UR); Biofiltered, Hydroton (BR); Biofiltered, pumice (BP); Biofiltered, raft (BR).

Figure 25. Nitrite results for weekly water tests from the three 'tap water' and three 'nutrient control' boxes. Treatments: Tap water, Hydroton (TP); Tap water, pumice (TP); Tap water, raft (TR); Nutrient, Hydroton (NH); Nutrient, pumice (NP); Nutrient, raft (NR).

Figure 24. Phosphate results for weekly water tests from the three 'biofiltered' and three 'unfiltered’ boxes. Treatments: Unfiltered, Hydroton (UH); Unfiltered, pumice (UP); Unfiltered, raft (UR); Biofiltered, Hydroton (BR); Biofiltered, pumice (BP); Biofiltered, raft (BR).

Figure 23. Phosphate results for weekly water tests from the three 'tap water' and three 'nutrient control' boxes. Treatments: Tap water, Hydroton (TP); Tap water, pumice (TP); Tap water, raft (TR); Nutrient, Hydroton (NH); Nutrient, pumice (NP); Nutrient, raft (NR).

91

The nitrate results for ‘biofiltered’ and ‘unfiltered’ treatments (Figure 20) showed an

increasing trend, which was statistically significant for the pumice (BP and UP) and

Hydroton (BH and UH) media but not for the raft (BR and UR) setups. Over the measured

period, the ‘biofiltered effluent’ measured at the end of the biofilter also showed a significant

trend of increasing over time. The nitrate results from the tap water boxes (Figure 21) were

consistently low, below 0.40 mg/L. The nitrate results for the nutrient mix started high, at

around 30 mg/L on Day 0, and then dropped over the next few weeks to below 5 mg/L.

Figure 27. Total ammonia nitrogen results for weekly water tests from the 'biofiltered' and 'unfiltered' boxes. Treatments: Unfiltered, Hydroton (UH); Unfiltered, pumice (UP); Unfiltered, raft (UR); Biofiltered, Hydroton (BR); Biofiltered, pumice (BP); Biofiltered, raft (BR).

Figure 26. Total ammonia nitrogen results for weekly water tests from the 'tap water' and 'nutrient control' boxes. Treatments: Tap water, Hydroton (TP); Tap water, pumice (TP); Tap water, raft (TR); Nutrient, Hydroton (NH); Nutrient, pumice (NP); Nutrient, raft (NR).

Nitrite results (Figures 22 and 23) were lower than nitrate, but significantly increasing trends

were detected in the ‘biofiltered’ raft treatment (BR), and the three ‘unfiltered’ treatments

(UP, UH, UR). Very low readings were measured in the tap water control boxes (Figure 23),

at around 0 mg/L, and for the ‘nutrient control’ experiments boxes, the nitrate concentration

ranged from 0.400 mg/L to 0.

The phosphate charts (Figures 24 and 25), show that the concentrations of phosphate are

quite low and variable, with some measurements giving negative results. Nevertheless, a

statistically significant trend of increasing concentrations was calculated for the ‘biofiltered’

pumice (BP) experiment box, and the ‘biofiltered’ Hydroton (BH), as well as the ‘unfiltered’

pumice (UP). The ‘tap water’ control and ‘nutrient’ control charts (Figure 25) show similar

patterns to the other nutrients measured, with results around 0 mg/L for the tap water, and

declining phosphate concentration from an initial high of around 15.00 mg/L on Day 0 for

the nutrient control.

Total ammonia nitrogen (TAN) is an important measure, but the results show very low, very

variable and sometimes negative results, with large error bars (Figures 26 and 27). The

regression analysis does show significantly declining trends in the TAN data for ‘biofiltered’

pumice (BP), for ‘unfiltered’ Hydroton (UH), and for the unfiltered effluent samples

measured in the ‘pump tank’ over the course of the experiment. Because of the low precision

of TAN samples at such low concentrations, caution will be used when interpreting the

results in the next chapter.

3.3.3 Microalgae growth

Photographs were taken regularly during the experiment to monitor the progress of the

cultures. Figure 28 shows the series of photos indicating increasing concentrations of algal

culture in all experiment treatments. Note the variable colours between the treatments, which

will be addressed in the discussion.

Figure 29 illustrates the change in absorbance of the microalgae cultures over time. This

represents the increasing optical density of the algal cells (algae growth) in the containers.

The two nutrient rich water sources, ‘unfiltered’ and ‘biofiltered’, had no more microalgae

growth than the ‘tap water control’. None of these three treatments resulted in as dense a

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microalgae culture as the ‘nutrient’ control experiment, which showed increasing optical

density throughout the whole experiment.

Figure 28. Microalgae concentrations in the four different experiment boxes over 28 days.

Figure 29. Optical densities of the algal cultures over time, measured at 640 nm.

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 3 6 8 12 14 17 19 27

Ab

sorb

an

ce a

t 6

40

nm

Days

Optical Density of Nannochloris sp. in 30ppm saltwater

Tap-water

Unfiltered

Biofiltered

Nutrient mix

Poly. (Tap-water)

Poly. (Biofiltered)

Poly. (Nutrient mix)

To compare the optical densities with the algal biomass in the containers at the end of the

experiment, a scatterplot was created (Figure 30), but the error of the biomass technique is

too big to give meaningful results.

Figure 30. Absorbance at 640 nm plotted against the biomass (g/L) of samples from each algal treatment. Error bars for the biomass calculation come from the range of measurements made on five replicates from each experiment box. The error bars on the x-axis, absorbance, are from replicate absorbance measurements on the same sample.

0.1

0.2

0.3

0.4

0.5

0.6

0 0.2 0.4 0.6 0.8 1 1.2

Dry

mas

s g/

L

Absorbance at 640 nm

Absorbance v Biomass, Day 27

Tap water

Unfiltered

Biofiltered

Nutrient mix

95

4 Discussion and Conclusions

4.1 Discussion of Matorka results

As detailed in Chapter 2, the trial aimed to:

• Characterise the water at various points in the Matorka production process and

determine the best water source(s) to use for hydroponic plant growth.

• Test various hydroponic systems and compare the productivity of plants grown under

these different conditions.

• Test the efficacy of the different hydroponic systems as a means of removing

nutrients.

• To calculate the optimal amount of plant biomass that should be planned to utilise

the nutrients in the Matorka waste-water stream.

The discussion addresses these aims.

4.1.1 Characterising the Matorka effluent

The nutrient analysis confirmed that of the Matorka facility sites tested (excluding the

biofilter and experiment sites), the water used for the trial (‘pump tank’ results in Table 12;

number 6 in Figure 3), which was pumped from the ‘raceway’ at the end of the Matorka

system, had the highest concentrations of nitrates, nitrites and phosphates. Ammonia results,

while not very reliable, were also higher in the pump tank and in the effluent running to the

river (sampling location 7 in Figure 3). These results confirmed the advice of the Matorka

staff, who estimated that the water from the raceway had been used the most by fish and

Char, October 2012 (I. Flett)

would have the highest levels of waste, as well as being warm enough for plant growth

without having to dilute the nutrients with more fresh hot water (Sveinbjörn Oddsson,

personal communication, September 2012). This water was a good choice for the aquaponics

trial, and should be considered for any future aquaponics developments.

The water analysis also confirmed the efficacy of even a small biofilter like that constructed

at Matorka. By providing high surface area substrate (pumice) for the growth of a biofilm,

the biofilter amplified the nitrites and nitrates in the unfiltered water samples (See Table 12).

Biofiltration also seems to result in the expected reduction of TAN (as it is converted to

nitrites), with the average of the unfiltered water samples being 0.11 mg/L for TAN and the

average at the end of the biofilter, 0.09 mg/L (however note previously stated caveats on

TAN analysis). The nitrification process occurring in the biofilter is confirmed by the lower

pH readings in the biofilter as compared to those in the pump tank on every occasion the

pair of samples were measured. Reduced pH is one of the markers of nitrification activity.

An additional benefit of the biofilter was in reduced TSS. Comparing the average TSS

measurements on water from the end of the biofilter (0.7 mg/L) and unfiltered water from

the pump tank (57.0 mg/L) confirmed that the biofilter design removed more suspended

sediments than the pump tank, although both apparatuses slowed the water stream and

allowed suspended sediment to settle. When the biofilter was aerated (which was done

occasionally to flush the pumice of accumulated sediment which impedes biofilm growth),

the water sampled soon after had a higher TSS reading of 22.8 mg/L.

4.1.2 Growth under different conditions

The plant growth trials at Matorka showed that it is indeed possible to grow edible plants

and at least one species of marine microalgae using the nutrient-rich effluent from the fish

farm.

The plant growth characteristics measured at the end of the experiments (Figures 16, 17 and

18), indicate that the plants in the three ‘biofiltered’ experiment boxes had the best growth,

however when tested for statistical significance, the ‘biofiltered’, ‘unfiltered’ and ‘nutrient

control’ populations were not significantly different from each other for any of the measured

parameters. Plants in the “tap water control” experiments produced the lowest percentage

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change in all parameters, as expected, with significant differences from the two experimental

treatments (and the ‘nutrient control’) confirmed.

Because ‘unfiltered’ and ‘tap water’ plants were not significantly different from each other

for change in plant length, whereas ‘biofiltered’ and ‘tap water’ were, we can confirm that

there are some differences between the ‘unfiltered’ and ‘biofiltered’ treatments, which would

make the biofiltration worthwhile. This was expected to be the case, since we know from

the chemical analysis that the biofilter increased the plant-available nitrate compared with

unfiltered effluent.

During the experiments, algal colonies (probably incorporating bacteria) of unknown species

were observed on the unfiltered and biofiltered treatments (see Figure 15). Algae was

particularly intense on the ‘unfiltered’ treatments with pumice and Hydroton, where it was

observed to inhibit the flood and drain mechanism of the siphon, presumably by filling pore

spaces in the growth media. The algal growth was removed by hand where it was growing

on or near the plants, and when it started to block the tubes and fittings delivering water to

the experiment boxes or prevent complete drainage in the growth media. The biofilter

filtered out more of the suspended solids than the amount that was settled out in the pump

tray (since TSS measurements were higher in the pump tray than the biofilter), so it seems

that the solid waste contributed to the increased algal growth on the ‘unfiltered’ experiment

boxes, and therefore, that the mechanical filtration provided by the biofilter was effective.

Comparison of the three growing systems, Hydroton, pumice, and raft, (Figure 19) indicates

that the plants performed better in the Hydroton and the raft systems, with significantly less

growth in the pumice for at least one of the growth parameters. These differences are not

understood, but it is possible that the lower surface area of the pumice compared to the

Hydroton, or something about the micro-structure of the two medias’ different surfaces,

limited nitrification, or caused algae and bacteria to inhibit plant growth in the pumice

treatments but not the Hydroton.

The plants still performed well in the pumice, so if Matorka were to scale up the experiments

to a commercial scale, they would have to consider whether the lower cost, and improved

sustainability of using the local pumice balanced out the slightly reduced plant performance.

There might also be handling issues that the technicians could pay attention to, to decrease

the negative effect of the pumice. The pumice pieces are sharper than the Hydroton, so care

must be taken to handle plants very carefully when transplanting so as not to damage the

roots. Different sized pumice could also be used to experiment with. Smaller pieces would

provide more surface area for the biofilm to grow on.

It was assumed that the solid growth media would have had advantages over the raft method,

since the media provide high surface area for nitrifying bacteria to inhabit, however

significant differences were not found between the raft and the solid growth media in this

experiment. There could be advantages for Matorka in using the raft technique for future

aquaponics development, since it is generally simpler (no flood and drain valves required),

cheaper and easier to clean. The raft system used for the experiment did not incorporate any

shading of the water to try to limit algal growth. Polystyrene or wooden covers (with holes

for the plants) are often used to stop light reaching the water where non-beneficial algae can

grow, diverting some of the nutrients that would otherwise be used by the plants (e.g. Hu et

al, 2015).

The growth of algae and bacteria is potentially inhibiting to the plant growth (Rakocy, et al.,

2008; Heath, et al., 2010), and could explain the slightly reduced growth seen in the

‘unfiltered’ compared to the ‘biofiltered’ experiments, however in general, the size and

significance of differences between the two treatments were not as great as might have been

predicted. This could be because of the limited time for the experiments (perhaps differences

due to nitrification increase over time), because the nitrification that occurs within the grow

beds (themselves working as biofilters; Somerville, et al., 2014) and other parts of the system

(for example, within the pump tank where sediment could settle), is perhaps very important

to the plants, or because the biofilter was not working at optimal efficiency, potentially

because of other organisms living inside it (Heath, et al., 2010).

Microalgae

The microalgae experiment (Figure 28) showed that the nutrient-rich fish water effluent,

while not promoting as dense a growth of microalgae as the commercial nutrient mix, did

allow the microalgae to grow. As a way of stripping nutrients from the effluent,

Nannochloris sp. has potential. Further experimentation and analysis could pin-point any

missing micro-nutrients that could be added to the effluent to optimise microalgae growth.

Attempts to quantify the different concentrations of microalgae cells in each treatment by

drying subsamples of each, did not show the differences in concentration observed by the

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optical density technique (Figure 30). It is possible that differential evaporation had affected

the treatments, so that a 50 mL sample of each had unrepresentative concentrations, or that

salts absorbed onto the algal cells walls. Rocha, et al. (2003) note that this might be a problem

with microalgae dry mass calculations, and also that the cells could have different sizes and

weights depending on the growing conditions. Fifty mL samples could also be too small a

sample size to demonstrate real differences in concentrations given the precision of the

drying technique.

The strong growth even in the nutrient-poor tap water experiment shows that the microalgae

is not sensitive to nutrient levels and can be grown anywhere there is enough light, at least

for the first month. Nitrate and phosphate concentrations measured in the cold and hot spring

water at Fellsmuli, while low, were not zero (see Table 12), so perhaps the groundwater has

enough nutrients for algae growth. One noteworthy point, however, is that the tap water

experiment box in the experiment room was located at a higher level than the other three

microalgae growth boxes (i.e. closer to the light). It is not known whether this had an effect,

but Rocha et al. have shown that Nannochloropsis sp. (a different strain of marine

microalgae) cultures were very sensitive to light intensity, temperature and pH.

Another point is that the microalgae in the tap water experiment had a different colour to the

other boxes, as can be seen in Figure 26. This might be related to growth of bacteria or a

different species of microalgae, something that Rocha et al. (2003) note is very difficult to

avoid in uncovered growth conditions. However, Myers et al. (2013) found that when they

grew cultures of a different microalgae, Nannochloropsis sp., in high nitrogen conditions the

colour of the culture was a darker green than the yellow-green of a low nitrogen culture.

They found that this was related to the pigment in chlorophyll, with lower amounts of

chlorophyll in the low nutrient culture, and that it strongly affected the OD measurements at

680 nm (chlorophyll absorbance peak) but not at 550 nm, which they noted was a more

robust wavelength to measure OD at (Myers, et al., 2013).

Future research on the microalgae could focus on making sure the growing conditions are

exactly equal, and that the laboratory techniques chosen are refined for the particular species

and growth media. No experiments were conducted to assess the species’ response to

different salinities, although this would be interesting.

4.1.3 Efficacy of nutrient removal

Nutrient measurements made on the FIAlab system at Matís were unfortunately not always

consistent, so there is some uncertainty about their meaning, but they can be interpreted to

show some of the expected variations in nitrate and nitrite as nitrifying bacteria worked over

the course of the experiment. However, the main point to note about the results is that they

all show very low concentrations (except the nutrient-rich control). In the aquaponics

literature, <5 mg/L is considered too low a concentration of nitrate for plants to grow

successfully (Somerville et al., 2014). The Matorka flow-through system, therefore, was

flushing very dilute levels of nutrients through to the raceway and then on to the aquaponics

experiment. Figures 20-27 show the nutrient measurements made with the FIAlab system on

the samples from the experiment boxes.

As explained in Section 3.1.4, in a recirculating system, as nitrifying bacteria colonise and

start to work, ammonia levels are expected to rise for the first 10 days, then nitrite levels

should rise with lowering ammonia (Nitrosomonas conversion), and then falling nitrite

levels occur with rising nitrate (Nitrobacter conversion). Complications are that fish are

constantly introducing more ammonia, plants are using up the nitrate, and the Matorka

system was flushing though, not recirculating, meaning that concentrations of all the analytes

resulting from the bacterial conversions could be lower, and perhaps not follow the same

sequence of concentration changes. Nitrite and nitrate are formed by bacteria in biofilms

throughout the fish growing areas and piping, too, but the highest concentrations were

expected at the end of the biofilter, and in the water that was flushed through the growing

media by the syphon systems (sampled each week for the ‘experiment boxes’

measurements).

The nitrate results in Figure 20 show the expected increase in concentrations in the

‘unfiltered’ and ‘biofiltered’ experiments from the 1st of October (Day -21) until the end of

the experiments. Nitrate results from the first sampling day, on the 25th of September (Day -

27) were all very high compared to other days (even for the ground water and other system

water), and possibly indicate an error in the laboratory procedure. For this reason they were

excluded from the analysis.

No significant differences were noted between hydroponic systems, indicating that the raft

system had enough surfaces for beneficial biofilms to form. Levels were also similar

101

between the ‘unfiltered’ and the ‘biofiltered’ experiments, indicating that both systems are

suitable for generating plant-available nitrogen. Falling but high levels of nitrate in the

‘nutrient mix’ control experiments could indicate the use of the nitrate that was in the

commercial hydroponic mix by the plants, although the very low levels at the end are

surprising. Perhaps a denitrification process (with N2 or NO2 being released) was also

occurring. Consistently low levels of nitrate in the tap water box gives confidence in the

technique, and also shows the probable sensitivity/precision of the nitrate analysis.

The nitrite results in Figure 22 tell a similar story, although with more variability in the result

ranges, possible because nitrite is produced by some bacteria and used by others. Nitrite

levels climb during the experiment in the ‘unfiltered’ and ‘biofiltered’ boxes, with

significantly increasing trends in all three ‘unfiltered’ and the ‘biofiltered’ raft. This

presumably indicates the ongoing conversion of TAN that enters the experiment from the

fish effluent, into nitrite.

Phosphate concentrations (Figures 24 and 25) are very low for the ‘tap water’, ‘unfiltered’

and ‘biofiltered’ experiment treatments, and the variability observed might indicate that

results under 0.20 mg/L are under the detection limit for the technique. The phosphate results

closely mimic the nitrate results for the ‘nutrient mix’ control experiment boxes, which might

show the uptake of the nutrients from the commercial hydroponic solution by the plants, or

could be the result of some other process (e.g. settling of concentrated mix somewhere in

the system or incorporation of nutrients into biofilms that have formed on system

components).

Three factors could have contributed to results not being as clearly different between the

experiments treatments as might have been expected:

• The overhead light might have favoured the plants in the central area, and not been

as intense at the edges of the experiment area. Figure 6 shows the experiment setup

as it was, with the overhead light directly above the middle of the array. It is not

known how big an impact this effect might have had on the results.

• The positions of the plants in the boxes might have had an impact on their

performance. For example, a plant that was close to one of the spray points might

have had more access to nutrients, or been in an optimal position for the

wetting/drying effect of the flood/drain system, or been too close to the spray and

splashed on the leaves or covered in algal growth more than the others. It is assumed

that the randomised positioning of the plants, with the three species in various

locations around each box, plus the fact that there were four replicates of each species

in each box, would have averaged out any differences in growth related to box

position.

• Nitrification was probably occurring in the ‘pump tank’ as well as in the biofilter.

Biofilms and micro-organism growth was observed on the settled sediment in the

pump tank. This could have reduced the difference between the ‘unfiltered’ and

‘biofiltered’ treatments, especially in the raft treatments, where the lack of growth

media should have resulted in different nutrient availability between the two

treatments.

The most logical way to estimate nutrient uptake by plants would be to compare the nutrient

levels in the water flowing into the experiment (biofiltered and unfiltered effluent) and the

water flowing out (the siphon drain valves, which is where the experiment water was

sampled). Figures 20, 22, and 24, however, show that significant differences between the

effluent going in and the experiment water, were not detected by the analysis.

Probably the main limitation of the experiment design was its short length. Most experiments

with aquaponics aim to get the plants to a mature or harvestable size before measurement

(Skar, et al., 2015), and this could have amplified some of the plant growth differences,

evened out some of the variability within treatments, and perhaps once the plant biomass

was high enough, allowed the nutrient uptake to be measured. However, differences were

still observed in the different treatment boxes, which can be attributed to the varied rates of

nitrifying bacteria effectiveness due to different treatment parameters.

4.1.4 Developing aquaponics at a commercial scale in southern Iceland

By design, this was a small, short, low risk experiment intended to explore the hypothesis

that a flow through aquaponics system would be a suitable addition to Matorka’s business.

The results could have been much more robust and useful to other organisations if the

experiment had continued for a longer period (for example, ~100 days until harvest of the

vegetables would have been possible).

103

So that the cost of experimental set-up was low, everything was designed to fit under one

grow lamp and be built out of repurposed or cheap materials. A commercial scale aquaponics

set-up for Matorka would be much bigger and have some more professional parts. For

example, the bell siphon drainage valves were hand built and tricky to perfect. There were

times when the flood and drain mechanism wasn’t working well, and so nitrification

processes may not have been optimal.

Matorka is located in a stunning part of Iceland, with low intensity farming, or natural

uninhabited areas all around. In 2012 their water treatment was only some settlement of the

effluent before it flowed directly into an important salmon stream (Figure 31). The high-

volume river and the high flow-through rate of the facility (which was sustainable because

of the excellent, low cost warm and cold groundwater available) meant that environmental

impact was negligible and within regulated limits (Sjöfn Sigurgísladóttir, personal

communication, September 2012).

Figure 31. Part of the Matorka facility at Fellsmuli, on the bank of the Minnivallalaekur River. Some of the outdoor Arctic char tanks can be seen, and the side of the building housing the experiment.

Despite conforming to the regulations, the company was keen to reduce their environmental

impact as much as possible. The simple flow-through system that was designed undoubtedly

resulted in lower nutrient levels than recirculating systems can generate (Pantanella, 2012),

and further experiments at Matorka were conducted in 2013 and 2014 to work out the details

of a possible recirculated aquaponics component to the business (Skar, et al., 2015).

However, the simplicity of a flow-through system which treats high nutrient aquaculture

effluent that would otherwise be released into the environment is still very appealing for

companies like Matorka, and as an example for other land-based aquaculture in Iceland.

Because nutrient uptake results could not be calculated during the 2012 experiments

conducted during this project, I next turned to using figures from the literature to attempt

calculations to estimate reduction in nutrients in effluent, based on growing edible plants.

However, the nitrogen budget calculations are extremely complex (e.g. Endut, et al., 2014),

with many unknown parameters in this case (e.g., nitrogen input rate as fish feed, when water

sourced for the experiment came from multiple tanks, with different feeding rates, and

somewhat arbitrary dilution steps added), plus important differences between published

examples and this experiment (primarily that in RAS nitrogen budgets, the water passes

through the cycle multiple times). So unfortunately, no firm recommendations can be made

about optimal plant production rates in any scaled up system. There are some general ideas

gleaned from the literature about what a good commercial system could look like but more

experimentation and calculations would be required to determine the optimal size:

• A number of authors give simple calculations for the ratio of fish to plants, or more

accurately, fish feed to biofiltration and plant growing area, for setting up a

recirculating system. For example, a fish tank of 1000 L, stocked at 20 kg fish

biomass, requires a feed rate of 200 g/day (10 g/kg of fish), pump flow rate of 2000

L/hr, filter volume 100-200 L, a minimum of 200 L of biofilter medium, and a 4 m2

plant growing area (Somerville, et al., 2014). At these rates, and under optimum

conditions, a steady state of plant and fish growth and nutrient removal can be

established. The pump rate suggested would allow the system water to pass through

twice per hour, giving the plants much longer contact time with the water than in the

experimental flow-through system.

• A combined system that recirculates the water around the biofilter and the grow beds,

but not back to the fish should be developed, to give the nitrifying bacteria more

opportunities to work, and the plants more contact with the water. The volume of

recirculating water would have to be partially exchanged at regular intervals in order

to treat new volumes of water while maintaining some of the nitrifying bacteria. A

ratio of plant growing area to feed rates could be calculated using Somerville et al.’s

suggested rates.

105

• A biofilter to provide nitrification substrate is recommended based on the experiment

results. But a mechanical filtration step should also be included to reduce sediment

build-up in the biofilter, which can reduce performance and potentially lead to

anaerobic conditions. The sludge from this filter has been used in other systems as a

fuel for combustion to create biogas, or a fertiliser which could be an additional

marketable product (Yogev, Barnes, & Gross, 2016).

• The superior plant growth results in Hydtron and raft culture could be weighed up

against the cheap, local and also quite effective pumice.

• Leafy greens and herbs are recommended in lower-nutrient systems. Because Iceland

already has a well-developed greenhouse/hydroponic industry, there is an established

market for vegetables and herbs produced in this way. That means that the

regulations, expertise and retailers are already in place and ready to accept

hydroponic plant products, and need not limit immediate development. Identifying

products that are currently imported to Iceland, and producing those, could give the

company an advantage.

• Some of the water could be diverted to culture tanks for microalgae. This microalgae

may be able to contribute to fish feed production, or sold as a product. Experiments

with Icelandic macroalgae species could also be beneficial. In one system in

Hungary, the effluent that goes to the microalgae tanks stays there until it evaporates

(Bittsanszky, et al., 2016), eliminating the effluent entirely.

• Innovative research and technological advancements should be sought and

contributed to.

• The philosophy of focusing on the fish sales and maintaining high quality of those

products is sound. Any additional money made from the treatment of the effluent

with plants should be seen as a bonus. Matorka already exploits the ‘green

credentials’ advantage of producing the fish without fossil fuel input (carbon

neutral). Consumers may pay a premium for this at the moment, and it is possible

that because of carbon trading in the future, products that are produced with fossil

fuel energy will have the cost of the greenhouse emissions built in, making products

like Matorka’s Arctic char even more competitive.

• The same can be said about other environmental impacts that could have a price in

some markets (or in the future). For example, for land-based aquaculture systems

that put a nutrient load into waterways that does exceed local water quality

guidelines, in some places fines or levies could result. Installing aquaponic effluent

treatment could mean that the company could avoid these payments, plus the

products could be marketed as being more sustainable. Further discussion about

marketing opportunities for sustainable aquaponics products follows in Section 4.7.

Some more ideas about how Matorka or other commercial farms could transform their

system to be more like an agroecosystem are listed in Table 14, Section 4.4.

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4.2 Aquaponics strengths and opportunities

The aquaponics literature summarises the advantages of aquaponics as:

• Reduced water usage and waste (Diver & Rinhehart, 2010).

• High nitrogen utilisation efficiency compared to aquaculture (34%-41% compared

to 25%), which necessitates clearing nitrogen compounds from the aquaculture

system to avoid poisoning the fish, thus losing those nutrients (Hu, et al., 2015).

• Improved profitability (over hydroponics or aquaculture) due to multiple crops being

produced (Tyson, et al., 2011).

• The Aquaponics NOMA report, in which some of the results from the Matorka

experiments were included, highlights certain benefits of aquaponics for the Nordic

countries including Iceland (Skar, et al., 2015):

o Extremely water and nitrogen efficient, with two agricultural products

created from the same inputs

o Organic-like management and production (and does not use any chemical

pesticides or fertilisers)

o Daily and seasonal tasks create inclusive job opportunities

o Does not require soil and can be used on non-arable land such as deserts,

degraded soil or salty, sandy islands

o Sustainable and intensive food production system

Responses from the community survey about the positive aspects of aquaponics are collated

in Table 9. The responses focus on self-sufficiency and knowing where one’s food comes

from, that it is fun, and that you can make money doing it.

These ideas about strengths and opportunities (the positives of aquaponics) are

discussed in the following sections: Resource efficiency, particularly of nitrogen and

phosphorus, which are essential for agriculture but not in unlimited supply. Making

money – case studies show that it is genuinely possible. Industrial food production has

issues, some of which aquaponics can address. A related issue is about consumer choice

– people around the world are consuming more consciously and aquaponics is in a good

position to take advantage of this opportunity. And finally, aquaponics is for everyone,

at the backyard, community or commercial scale, and also in developing country

contexts.

4.2.1 Resource efficiency

Aquaponic science has resource efficiency at its heart. Water, nutrients, human capital, and

energy inputs are all used to create more products than separate plant and fish growth would

on their own. In the case of water, the resource is used repeatedly since multiple plant and

fish crops can be grown in the same water. Furthermore, the aquaponics community is very

interested in sustainability, environmental protection, and the use of renewable energy

(Love, et al., 2014). There are many discussions about how to get a hold of old ‘IBC’ cubes,

or bathtubs to use as grow beds. The aquaponics community loves recycling.

In terms of the science of resource efficiency, aquaponics can make a contribution to the

important field of nitrogen management. Nitrogen fertilisers are produced by an industrial

process, which has greatly increased worldwide crop production, allowing economic

development and possibly sparing forests from conversion into new agricultural land

(Zhang, et al., 2015). However, because an estimated one billion people are currently

undernourished (FAO, 2017), and the world’s population is predicted to grow significantly,

the demand for nitrogen fertilisers will increase, and careful management of nitrogen will be

required (Zhang, et al., 2015).

Zhang, et al. (2015) looked at the measures of nitrogen-use efficiency (NUE), nitrogen

surplus (Nsur), and nitrogen yield (Nyield), which they explain can serve as targets for

agricultural efficiency, environmental pollution, and food security, respectively. At a global

scale, NUE, which is defined as the ratio of Nyield (outputs; the nitrogen in crop products) to

Ninput (the nitrogen inputs), must be dramatically improved, by reducing the Ninput while

increasing the Nyield (Zhang, et al., 2015). Meanwhile, serious environmental pollution is

caused by nitrogen losses from agricultural systems, Nsur (Nsur = Ninput – Nyield). This includes

local eutrophication, and regional ecosystem damage (Knaus & Evershed, 2017), both from

nutrient-rich runoff, and the global impact of the greenhouse gas, nitrous oxide. Nitrogen

use efficiency improvement, is therefore vital for dealing with three of the biggest challenges

humanity faces – food security, environmental degradation, and climate change (Zhang, et

al., 2015).

The authors state that the only way to achieve the required NUE targets is to launch a global

program with ambitious global and national targets, based on (increased) routine data

collection to track the three indices (Zhang, et al., 2015).

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Increasing aquaponics is a way countries could strive to meet their NUE targets. By growing

plants on the nitrogen that has already been used to grow protein, with no added Ninput, and

in the case of RAS aquaponics at least, very little Nsur, most of the nitrogen becomes Nyield,.

Compared to conventional agriculture, NUE is improved, the reduced Nsur has positive

impacts on the environment, and a high Nyield, especially if it is a trend across a whole

country, is an indicator that local food productivity, and food security, is improving.

4.2.2 Making money

Some of the focus in aquaponics literature is on whether aquaponics can be a profitable

business. It is often said that a niche market is required since industrial agriculture can

produce products so cheaply (Rakocy, et al., 2008).

Tokunaga et al (2015) report there are four commercial scale aquaponics enterprises

operating in Hawaii, and looked at the feasibility of establishing an aquaponics industry

there. The researchers showed that the three farms studied are yielding a positive profit, and

in the model case they constructed, given the costs for setup, operation, sales prices and

depreciation of assets, aquaponics businesses are feasible with a modified internal rate of

return of 7.36% (Tokunaga, et al., 2015). The most sensitive economic indicator there is

lettuce price, with profits dramatically increasing if the sales price of lettuce increases by $1.

Organic certification or an ecolabeling scheme highlighting aquaponics’ sustainable

production methods could lead to higher prices for products. Tokunaga et al (2015), based

on the Hawaiian examples, emphasise the importance of understanding the market: the

overall economic balance is very sensitive to product prices, so it is essential to know how

much produce the market can absorb, and at what price.

Elsewhere, researchers in Egypt showed that aquaponics using a raft system was productive

enough to be a good business model compared with growing the same products using

traditional agriculture, and that the raft system was more cost effective than a similar sized

NFT system (Goda, et al., 2015).

In NSW, Australia, Rupasinghe and Kennedy (2010) compared the projected values for

commercial barramundi and hydroponic lettuce production as stand-alone units, and

alternatively as a combined aquaponics system. Over ten years, the integrated system would

have had a net benefit due to reduced costs of fish waste disposal and hydroponic nutrient

inputs.

Calculations in Iowa demonstrate that a commercial tilapia-basil aquaponics set up would

be economically viable, with the price and availability of the basil being more important that

the fish production for the profitability (Patillo, 2017).

Survey respondents were also encouraging about the profitability of their aquaponics

experiences, with 41% saying that aquaponics is cost effective for them, 85% reducing

household costs by growing some of their own food, and half the respondents saying they

can make money out of running an aquaponics business. Love et al. (2014) reported that of

their 809 survey respondents, 84% were involved in aquaponics as a hobby, but a quarter of

these hobby farmers were also involved in commercial activities (selling crops, fish,

materials of services) to some degree.

Profitability in a commercial enterprise is probably reliant on four factors as discussed in

Section 4.3.3, so given the right community conditions, careful planning and good business

understanding, aquaponics is maturing into a good business opportunity for some groups

(Laidlaw & Magee, 2016).

Love et al. (2015) assessed 272 commercial operations (145 of these in the USA), and found

that while only 30% of respondents used aquaponics as their primary or sole income, this is

similar to the figure for small scale conventional farms (earning less than $50 000 per year).

The median gross sales revenue recorded in the survey was $1000 to $4999, with 10%

receiving over $50 000 (Love et al., 2015), indicating that the majority of commercial

aquaponics farmers are operating at a small scale. The authors correlated farm profitability

with five factors: primary income (if the farm was the owner’s primary income, likelihood

of profitability was five times higher than if not), USDA climatic zone (farms located in

places with mild winters, i.e., average annual extreme winter temperatures > -18 C, were

four times more likely to be profitable than those in places with cold winters), sales revenue

(farms generating incomes >$5000 were 3.5 times more likely to be profitable than those

under $5000), knowledge (respondents were classed as ‘more knowledgeable’ or ‘less

knowledgeable’, with a 2.37 odds ratio for profitability), and finally, sales type (where farms

could be in three categories, and those that a) only sold materials and services were more

likely to be profitable than those which b) sold plants, fish, materials and services, and both

a) and b) were more likely to be profitable than those who only sold c) only sold plants and

fish.

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4.2.3 Industrial food production has issues

The importance of fixing the problems of industrial agriculture and aquaculture have been

recognised by important international agencies, as well as multiple individual governments

and NGOs (FAO, 2017; The Christensen Fund, 2013; United Nations, 2015; United Nations

Human Rights Council, 2017; Altieri, et al., 2012).

Given the predictions for human population growth and increased protein requirements, and

our understanding of reduced wild catch rates, another concern is the use of wild fish for

purposes other than direct human consumption. Nearly 30% of the fish caught between 1950

and 2010 was not used for human consumption, and most of this went to fish meal and fish

oil for production of animal feeds (Cashion, et al., 2017). Additionally, 90% of that fish was

food grade. This is one big impact of aquaculture.

Other well-known effects of conventional aquaculture include: eutrophication in waterways,

especially nutrient pollution in marine systems around fish farms (Ross, 2017),

contamination of natural areas with antibiotics and chemicals used to treat fish being grown

in sea pens, infestations of parasites that affect wild animals too (Vidal, 2017), habituation

and harmful interactions between marine mammals and aquaculture managers,

contamination of gene pools by escape of farmed fish, and also, introductions of non-native

species (Ager, 2016). Simply, industrial aquaculture has environmental impacts that are “not

in accordance with the long-term sustainability of natural ecosystems” (Granada, et al.,

2015).

Turning to the land, industrial agriculture contributes about 25-30% of GHG emissions,

demands ever increasing inputs and produces declining yields, and is not distributed well

enough to feed the 1 billion hungry people of the world. One third of food produced is

wasted, and 25% of food purchased in the EU is wasted (Canali, et al., 2017). Over 500

species of insect have developed resistance to pesticides. More than half of industrially

produced food goes to feed animals and to produce biofuels (Altieri, et al, 2012). These are

just some of the disturbing facts about world food production.

An alternative is agroecology. Agroecologists promote “peasant agriculture”, small scale

local farming concentrating on traditional methods and crops with increased nutrient cycling,

less waste, and fewer impacts on natural ecosystems. Aquaponics uses agroecological

methods which mimic natural ecosystems and combat the problems we see in industrial food

production (see Sections 4.5 and 4.6).

4.2.4 Consumer choice

The expansion of the organic food market in recent years (e.g. 20% growth per year in the

US; Organic Market Analysis, n.d.) can be used as a proxy for the increasing interest that

the public has in eating healthy, sustainable, non-industrial food. In wealthier countries at

least, consumers are willing to pay a premium for food that meets their ethical standards.

Aquaponics products are theoretically able to achieve organic certification, and are also able

to meet other eco-labelling production requirements, for example, sustainable seafood

certification. This is a big strength of aquaponics, and an area for future growth.

4.2.5 Aquaponics for everyone

Aquaponics is a useful idea for so many groups of people. Backyard aquaponics can be set

up to run efficiently, contributing to household food supplies, providing a family hobby, and

an education resource for kids. Households can choose varying levels of self-sufficiency

from mains electricity, and a spectrum of system builds from a commercially produced kit

with instructions and training videos to “repurposed bathtubs strung together with Youtube

advice”. They can also choose which plants, which fish, and which gurus to try at different

times.

The prevalence and growing accessibility of technology including self-publishing web tools

means that technical experts in all fields are able to participate in global information sharing.

At the same time, there is a movement of academics losing faith in traditional publishing

methods and considering alternative models of open access publishing. This opens up

academic topics to more public modes of discussion, which both increases the number of

potential “reviewers” or critics, and also broadens the audience so that research techniques

and academic knowledge may be more easily transferred. In fields like aquaponics, these

two changes mean that anyone with an internet connection can access good quality

information and instruction. Additionally, it might reduce the amount of traditional academic

publication on the topic. As an example, there are several free newsletters and small

periodicals that focus on technical information rather than academic articles, which might

see a higher readership and more practical application (e.g. Aquaponics Journal, Oklahoma

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Cooperative Extension Service, Southern Regional Aquaculture Centre, Global Aquaculture

Advocate, OSU Fact Sheets).

This provides a strong sense of an aquaponics community which is friendlier and more

encouraging than, for example, government extension support services for farming, or

formal training systems through Universities. Combined with online forums, YouTube

videos and social media sites, there is technical support and encouragement available to

people all over the world. This is much the same as in permaculture, and in sustainable

lifestyle areas such as homesteading, self-sufficiency and even cooking.

At a slightly bigger scale, the community garden type of aquaponics has fantastic potential

for improving peoples’ lives. Traditional community gardens have been shown to have

benefits for health, wellbeing, and regional sustainability (DeMuro, 2013). They also

contribute to suburban food security, education aims and community cohesion (Laidlaw &

Magee, 2016). Community aquaponics projects have all these advantages, but can also

produce fish and other edible animals.

In urban settings, aquaponics has the potential to be run as a not-for-profit as described for

community gardens, but could also be a commercial business. The potential of urban

aquaponics is much discussed.

There are several small companies who have already demonstrated that aquaponics can be

conducted profitably in small compact, and even mobile units (World Economic Forum,

2015). Bringing food production into cities can reduce food waste (Thyberg & Tonjes,

2015), reduce transport costs and greenhouse gas emissions, and utilise poorly used city

spaces such as vacant lots, disused buildings, rooftops and industrial areas (World Economic

Forum, 2015; Laidlaw & Magee, 2016).

Urban farming is set to become much more important in the future, given population

projections predict that two thirds of the world’s 9.7 billion inhabitants in 2050 will live in

urban areas (FAO, 2017). Additionally, 75% of “food deserts” in the US are in urban areas,

so urban aquaponics farms could be part of the solution (Recirculating Farms Coalition,

2013).

Urban farms contribute to sustainable agriculture and food sovereignty by providing new

opportunities for resource efficiency, improving urban life for residents and workers,

encouraging innovation, and provide local food supply (Laidlaw & Magee, 2016). Thomaier

et al (2014) do point out, however, that the urban farms they looked at were in developed

countries, and all were in middle-income areas, therefore these particular enterprises were

not addressing the food security (developing urban areas), employment or access to fresh

cheap food (low income areas of developed countries) issues that urban farms could, in fact,

address. Instead, some of the studied farms had generated exclusionary effects and

inequalities related to high prices, image, and not providing what local residents actually

want (Thomaier, et al., 2014).

Laidlaw and Magee (2016) highlight the additional issue of financial viability in urban areas,

where electricity costs for lighting may be higher than in purpose-built agricultural

greenhouses, rent and rates might be at a premium, and economic pressures could be stifling.

In their Milwaukee example, the “for profit” side of the business failed, but the community

education and volunteer-run side flourished. The Melbourne example had smaller

aspirations and has had less community impact, although it is completely self-sufficient in

energy and water (Laidlaw & Magee, 2016).

Commercial aquaponics systems are usually the largest and have higher costs and risks

associated with setup, and must address issues that small scale aquaponics does not, such as

commercial food safety, and local environmental regulations. They have many advantages

over solely aquaculture and hydroponic systems, mostly due to the improved sustainability

and multiple potential product streams. Some disadvantages are discussed in Section 4.3.

Opportunities abound for commercial aquaponics (and other sustainable agriculture

methods) because of the growing need for sustainably produced food that does not have the

disastrous human health, human rights and environmental impacts that industrial agriculture

has (United Nations Human Rights Council, 2017).

Aquaponics for education. As mentioned in Chapter 1, there are some universities and

colleges around the world who offer training in aquaponics as stand-alone courses or as part

of aquaculture courses. High schools in many places have also embraced aquaponics as a

teaching tool, and for local food production. Adding an education element to an aquaponics

start-up helps to diversify and strengthen the business (Laidlaw and Magee, 2016).

In developing countries, aquaponics provides an opportunity for marginalised groups,

especially in coastal and rural areas, to take control of their own food production. This is

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particularly significant for women, indigenous groups and ethnic minorities. Aquaponics is

an opportunity to improve food security in places with poor access to transported food, and

in places where previous farming practices, drought or industry have reduced agricultural

productivity (Somerville, et al., 2014).

Techniques from aquaponics and IMTA can also be utilised for water treatment, soil

amelioration and environmental rehabilitation (Botha, 2014). In some cases this type of

regenerative farming can produce food while also improving water quality. This is the case

with the highly inspirational and award-winning business, GreenWave (GreenWave, n.d.).

The story of how Bren Smith started his ocean farming business (Smith, 2016) is incredibly

thought-provoking and encouraging. After winning a sustainable design award in 2015, his

restorative 3D marine farming technique received accolades and intense media interest

(Laylin, 2015; Goodyear, 2015) because of its promise to not only regenerate degraded

marine systems, but also produce food (sea weed, oysters, clams etc.), provide employment

in struggling fishing communities (initially in Rhode Island and New England), and be an

open source design that others could emulate. Unfortunately, his open source designs are

nowhere to be found yet, and inquiries via the company website are met with a message

saying they are too inundated with emails to reply, but nevertheless, it does seem to be an

incredible success story based on IMTA principles.

To summarise, one of the great strengths of aquaponics is its diversity and applicability to

many situations, from small-scale family operations, to community-sized systems which

have particular potential in developing countries and urban areas, to restorative farming for

environmental improvement, to commercial farms (with the big advantages of multiple

products, and sustainability credentials).

4.3 Weaknesses and threats

Identifying weaknesses and threats in the aquaponics literature is more difficult, because

many aquaponics practitioners are so positive about their experiments and results! However,

there are some issues that the industry has to work out in order to fulfil its potential. A big

weakness that aquaponics has, is its reliance on commercial fish feed which still contains

significant proportions of wild fish meal and oil: this diminishes the sustainable aspirations

of aquaponics, and potentially also its price/niche premium.

Survey respondents were asked if they had had any negative experiences with aquaponics or

with their interactions in the online community. Table 10 shows their answers, which are

mostly related to the fact that fish (and plants) can be killed easily be mistakes, that start-up

costs can be high, that bugs (pests) can be a problem, and that some of the advice given is

not always accurate.

The Aquaponics NOMA project identified some weaknesses which they stated should be the

focus of further “investigation and remedial action” (Skar, et al., 2015):

• Improving system design for optimal production of fish and plants

• Legislation in the Nordic countries for aquaponics start-ups

• Parameters to improve/increase investors’/producers’ turnover

• Fish and plant requirements do not always match perfectly

• Knowledge on fish, bacteria and plant production is needed for each farmer to be

successful, and mistakes or accidents can cause catastrophic collapse of the system

• Expensive initial start-up costs compared with soil vegetable production or

hydroponics

• Daily management is necessary, and management choices are reduced

• Energy demanding

• Requires reliable access to electricity, fish fingerlings and plant seeds

In the following sections, these weaknesses and problems with aquaponics are

summarised as: issues with know-how, the time and effort that aquaponics takes, some

of the costs and risks that aquaponics farmers face, regulation including food safety

concerns, and finally, unscrupulous salesmen, who have been referred to as ‘aqua-

shysters’.

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4.3.1 Know-how

Some of the aquaponics writers warn that commercial operations are tricky: “the operation

of such complex systems on a professional level is not for enthusiastic amateurs” (Pilinszky,

et al., 2015; Diver & Rinhehart, 2010). The Aquaponics NOMA (2015) report, and several

of the survey respondents highlighted the issue that an aquaponics manager has to be well

versed in three cultivation methodologies – plants, fish and microbes – for the farm to be

successful.

For a household, it can be very discouraging and traumatic to suffer loss of fish because of

a chemistry mistake or equipment failure. For a business, it could also be costly or

bankrupting. One study identified signs of (sometimes intentional) naivete in start-up

aquaponics businesses (Laidlaw & Magee, 2016). This manifested as a lack of market

analysis, poor understanding of governance structures, lack of business plans or cost-benefit

analysis of alternative system designs, and a reliance on good timing and optimism (Laidlaw

and Magee 2016).

Issues highlighted by the community survey respondents related to a lack of know-how

included: plant nutrient deficiencies, fish death, and the issue of not being sure how to get

rid of pests since most chemicals can’t be used.

4.3.2 Time and effort

None of the survey respondents listed this specifically as a negative, but it is known to be a

time-consuming hobby, and 12.2% (5 respondents) agreed that “Aquaponics is a lot of work

for not much reward”. At the backyard/family scale, once it is set up, it is not much more

work than having a conventional garden and pets that need to be fed every day. At the level

of a small business, it might be very labour intensive, especially during the set-

up/stabilisation phase.

A study of two small aquaponics enterprises in Milwaukee and Melbourne showed that

dependence on volunteers was a weakness because the systems do require ongoing

maintenance and it can be difficult to maintain volunteer enthusiasm (Laidlaw & Magee,

2016).

4.3.3 Costs and risks

The Milwaukee and Melbourne case studies in Laidlaw and Magee (2016) demonstrate that

it is difficult to overcome the high set-up costs of aquaponics, especially if a company does

not have the support of grants, private donations and volunteer assistance as these two

experimental, community enterprises did. The study demonstrated that four factors are key

to aquaponics success, and if they are not considered, then the viability of the enterprise

could be threatened (Laidlaw & Magee, 2016):

• Ongoing commitment of key stakeholders. Especially in community scale systems,

ongoing enthusiastic volunteers are required.

• Positive local political context, ideally reducing costs of licencing and compliance

with local laws.

• The availability of markets for produce. Even in urban areas this may be more

difficult than it sounds because food production costs (including water and energy)

in developed countries are externalised.

• Diverse business strategy (possibly including training and education).

Looking at the community survey results, six respondents (14.63%) agreed that “Aquaponics

is an expensive hobby”. One respondent acknowledged that it is a competitive market and it

could be better for sales if fewer people are involved: “We expect to sell more than $1 million

per year, and don't care at all about "aquaponics" as an industry... the fewer people doing

it locally, the better for us.” A couple of respondents mentioned that the low cost of

conventional food in the US makes it difficult to sell more expensive products, even if they

are healthier, e.g. “Making money on a larger commercial scale is a challenge in the USA

so far because of the price of conventionally produced food.”

Love, et al., (2015) found in their survey of 257 commercial aquaponics farms, only 31%

had been profitable in the previous 12 months. Although 50% predicted profitability the next

year, this still demonstrates that it can cost more than expected, and profitability is not

guaranteed.

4.3.4 Regulation

Laidlaw and Magee (2016) state that the political and economic context can have a big

impact on the success of a small aquaponics enterprise. While the Milwaukee case study

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they described had municipal support, the Melbourne one did not. This is possibly because

of the positive economic climate in Australia during the study period, and less of a focus on

issues of employment, community development and food security. The regulatory food

regime in Australia, with high licensing and compliance costs could dissuade aquaponics

innovation (Laidlaw & Magee, 2016).

In the community survey, although 48.78% (20 respondents) agreed that “The government

in my area should consider providing more funding/assistance to aquaponics”, several

respondents were also wary of government intervention:

• “I have a concern that the government will not create an environment conducive to

small business, so that could hinder the aquaponic industry as it grows.”

• “Like too many things, small Mom and Pop operations have been squeezed out by

large commercial ops.”

• “The government should not be involved, no need to ask for hand-outs.”

• “Keep the government out of Aquaponics... once you start asking for money they will

regulate it. If it/you have a good product at a good price people will come to you. If

you can make a profit or save your life this will get better on its own without any

government assistance”

• “Barriers - big business/agribusiness protecting their own interests, slow acceptance

by educational institutions, governmental ignorance of aquaponics as a valid

alternative form of agriculture.”

• “Too much regulation on small family community units”

4.3.5 Unscrupulous salesmen

Some respondents to the survey, and some of the active online commentators (Rakocy J. ,

2010), have mentioned that there are increasing numbers of people trying to make money

out of aquaponics, and that some of these would-be entrepreneurs are not as honest as others.

Some comments included:

• “Be aware of predators - aquaponic experts that sell you expensive systems for

$25,000 to $1,000,000 and they do not guarantee the system to make money. Don't

spend that kind of money.”

• “False and misleading information online.”

• “Many folks giving bad advice that has not been proven. Lack of trained

professionals to run systems.”

• “Many people are in it to make money, not to help society. Industry is in it's infancy.

Not much scientific data out there on aquaponics, so there is a lot of hearsay and

unsubstantiated opinions.”

• “I see more predators ripping people off with providing Get Rich Quick Training

that grows vegetables in half the time or 10 times more. Do not take any training

from people that tell you how to grow organic vegetables when they are not USDA

certified organic producers themselves or they have never been certified organic.

It is possible to grow 10 times more than the conventional farming but not in half

the time. It took years of research and hands-on to become the 1st. Aquaponic

System in Mainland United States to receive and maintain USDA Organic

Certification since April 2009. (Second around the world).”

• “I question whether many of the more publicised farms in the mainland (I believe

those on islands have more financial potential) could actually be profitable if you

removed the money they make from training. Sometimes it seems like a pyramid

scheme with them. The money is in the training, not in the farming.”

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4.4 Aquaponics as agroecology

“The greater the structural and functional similarity of an agroecosystem to the

natural ecosystems in its biogeographical region, the greater the likelihood that

the agroecosystem will be sustainable.” (Gliessman, 1998)

Using the ideas of Gleissman (1998; 2004) and Altieri (1995), an aquaponic system could

also be viewed as an agroecosystem, in which it would be advantageous for an aquaponics

farmer to copy, as closely as possible, the natural ecosystem upon which the agroecosystem

is based. For example, Gliessman’s agroecosystem diagram (1998) was modified to

represent an aquaponic system showing the elements of the agroecosystem (Figure 1 in

Chapter 1). This diagram allows the farmer or agroecologist to see the energy and nutrient

cycles as well as the external inputs and outputs (which may represent losses).

Figure 1 shows a hypothetical aquaponics agroecosystem, in which there are the living

elements, the products, and the nutrient and energy flows. Also represented are inputs to and

outputs from the system, which would vary over time, and could be analysed to determine

the ongoing sustainability of the system.

An agroecological approach is particularly suited to the field of aquaponics and IMTA

because modern agroecology has evolved into “transdisciplinary and participatory research

through engagement with social scientists, agricultural communities and non-scientific

knowledge systems” (Mendez, et al., 2013). Aquaponics, as it has been discussed in this

thesis is clearly an integration of knowledge derived from agriculture, aquaculture, non-

scientists and social scientists. While from some perspectives, that makes it seem

unapproachable and difficult (e.g. the idea that you have to be an expert in so many things

to be successful at aquaponics), it is also aquaponics’ strength. As with the ideal

agroecologies described by Mendez et al (2013), aquaponics, with its diverse community

base, and multidisciplinary foundations, is participatory, action-oriented and inclusive.

Table 14 details the way this idea could be tailored for a particular location or type of

aquaponic agroecosystem, and then the rest of this section explores the different elements of

the diagram with a view to using aquaponics to improve traditional aquaculture and see

whether the concept of an agroecosystem is valid and useful for the management of coastal

resources.

Table 14. Details of the agroecology model for different types of aquaponics systems, including a proposed Matorka upgrade including a custom-designed aquaponics system.

Matorka upgrade Ideal commercial Ideal backyard Ideal coastal

community or urban Saltwater option

Fish

Arctic Char, Tilapia; consider breeding herbivorous 'feeder' fish to contribute to feed production.

More than one species from multiple trophic levels. Omnivorous or herbivorous species to reduce feed requirements. Grow feeder fish as well.

Consider using non-edible species to concentrate on vegetable production. Otherwise, a local species, preferably herbivorous.

Carefully selected local species, fast growing, able to be bred in captivity. Grow feeder fish as well to contribute to feed. Consider brackish options.

Grow local native marketable species. Consider feeder fish species to reduce pressure on wild fish for fishmeal.

Plants

Marketable vegetables, high protein microalgae; investigate potential for grass crop production on surrounding land.

Diverse locally marketable vegetables and herbs. Add-on traditional agriculture to make use of solid waste and compost.

Huge range of options available depending on family/cultural preferences. Experimentation required.

Consider brackish/ marine options. Grow culturally appreciated produce. Use co u ity garde

model.

Excellent opportunities for algal species for human and livestock consumption and regenerative farming. Also salt-tolerant plants.

Microbes

Improve biofiltration, maximise surface area in growbeds, minimise anaerobic conditions, monitor temp and DO to ensure maximum nitrification.

Prioritise microbial health during setup, use expert consultation. Maximise growbed surface area, invest in electronic monitoring of chemical parameters.

Experimentation required to perfect nitrification. Consider commercial biofilter, filtration and aeration options.

Experimentation required to perfect nitrification. Consider commercial biofilter, filtration and aeration options. Focus available investment on this critical element.

Invertebrates

Feed species - worms, BSF larvae, research other insects. Investigate crayfish or shrimp as added product streams.

Include crayfish in freshwater systems and consider brackish/marine add-on for additional trophic levels (e.g. mussels). Grow insects on-site for fish feed.

Grow BSF larvae and worms as fish feed. Design waste system efficiently to re-use everything, e.g. household compost to BSF larvae. Consider growing crayfish.

Grow BSF larvae and worms as fish feed. Design waste system efficiently to re-use everything, e.g. compost to BSF larvae. Consider saltwater add-on for crayfish/mussels.

Ideal for multitrophic aquaculture – shrimps, oysters, mussels etc., both land-based and marine options possible. Consider growing insects for feed.

Products

Fish and vegetable processing onsite to make use of waste; aim towards fish food production onsite; sale of fish fillets, vegetables, crayfish, value-added products (e.g. marinated fish), possibly excess insect stock and possibly grass/hay or fertiliser.

Plan for either specialisation in a few products, or diverse seasonal multi-trophic products. Focus on food safety, labelling, legislation during setup. Explore options for selling products from waste, tourism potential, education, onsite food sale, value-added products

Products in backyard aquaponics are for home consumption and possible bartering in small co u ities or far ers markets. Experiment with preferences and new ideas.

Plan diverse seasonal multi-trophic products. Focus on food safety and legislation during setup. Explore options for making products from waste, tourism potential, education, onsite food sale, value-adding. Experiment with community preferences and new ideas.

Potential for niche, high end products such as seaweed. Many fish and shellfish options. Potential for fish feed and livestock feed ingredient production, biodiesel from algae, or the whole farm being used as a water quality treatment facility.

Solar and

renewable

energy

Maximise solar energy with greenhouses; very great competitive advantage available due to geothermal energy for heating and use of renewables for other electricity.

An ideal commercial facility would be built with electrical self-sufficiency in mind. Solar, hydro, wind or methane biogas production are all affordable options over the long term.

Maximise solar radiation for plant growth and heating. Consider installing rooftop solar and batteries if/when it is affordable.

Maximise solar radiation for plant growth and heating. Consider installing rooftop solar and batteries if/when it is affordable. Investigate municipal grants and support for renewable energy.

Renewable energy potential is similar for saline systems as for freshwater. For small-scale and community projects, it may be an investment to plan for in the future.

Atmosphere

and

precipitation

Free inputs from atmosphere and clean freshwater for fish production. Important to maintain image and preserve local environment by protecting the fresh water source and treating effluent.

An ideal commercial facility would capture rainwater and/or have a licence for fluvial or groundwater use. Water may need treatment in some locations, before using for fish, and especially before discharge.

Low water requirements for backyard aquaponics after initial setup. Tanks need to be covered to maintain chemistry balance. Local legislation for discharges should be followed.

Low water requirements for community and urban aquaponics after initial setup. Tanks need to be covered to maintain chemistry balance. Local legislation for discharges should be followed. Rainwater collection recommended.

Growing marine macroalgae for cattle fodder could be part of a greenhouse gas reduction strategy since cattle fed algae have reduced methane emissions. Potential for earning carbon credits under some schemes.

Recycled

materials

Research potential for recycling of municipal compost (e.g. as BSF larvae feed), increased use of fish factory and other

Opportunities for aquaponics companies to lead the way re-using compost for insect production. Waste

Backyard aquaponics lends itself to repurposed materials for tanks and growbeds. Opportunities for recycling and reusing

Community and urban projects can demonstrate effective reduce, reuse, recycle principles and have an important role in a

With good planning, marine and land-based saltwater systems could also build with repurposed materials where possible.

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food production waste in fish feed, aim to use repurposed and recycled materials for infrastructure construction where possible.

streams of aquaponics facility should be planned and recycled wherever possible. Repurpose construction materials where possible.

waste to grow insects and produce compost.

co u ity s environmental impact.

Growing lower order animals such as shrimps for fish feed using waste materials/compost.

Consumption

and markets

Local markets should be prioritised (as transport costs are a 'non-renewable human input'), products can be marketed as sustainable food, eco-labelling options should be investigated.

Local markets should be prioritised. Products can be marketed as sustainable food, eco-labelling options should be encouraged. Products may attract a premium for sustainability and health reasons.

The enticing aims of growi g o e s ow food are to reduce dependence on industrial food production, reduce waste, improve understanding of food origins, reduce household costs and reduce ecological footprint

Urban and community farms also aim to produce food locally to reduce dependence on industrial food production, reduce waste, improve understanding of food origins and improve community sustainability.

Local markets should be prioritised. Products can be marketed as sustainable, eco-labelling options should be encouraged. Products may attract a premium for sustainability and health reasons.

Renewable

human inputs

Human capital should be maximised to increase the positive benefit for local communities and economies.

Education, employment, and human health opportunities should be maximised to increase the positive benefit for local communities and economies. Progressive, sustainable employment practices required.

Aquaponics represents a learning experience for all family members. It should be noted that it requires daily care, like any animal-rearing method.

Excellent employment, education, and nutrition opportunities for urban, rural, and coastal communities. The Community Garden model of sharing works well. Thoughtful management is required.

Human inputs are similar to freshwater aquaponics, depending on scale. Encouraging example from GreenWave about employment opportunities for ex-fishermen.

Non-

renewable

inputs

Currently transport, unsustainable fish feed, packaging and building materials need to be analysed and minimised. This input is potentially much less in Iceland than in other places because of access to renewable energy rather than coal-generated electricity.

In most places, commercial fish feed, and energy for electricity and heating would be the main non-renewable inputs to minimise. Transport of products should also be considered, as well as unsustainable packaging, and seeds or fingerlings that ca t be bred on site.

Reducing the amount of unsustainable fish feed used should be a priority. Work towards renewable energy self-sufficiency. Minimise external inputs (e.g. commercial greenhouse supplies) where possible.

As with other types, commercial fish feed, and energy for electricity and heating would be the main non-renewable inputs to minimise. Priority to reduce these if facility is for demonstration and education purposes or in a high-profile location.

Consider the same issues as for freshwater facilities: work to reduce reliance on fossil fuels, plastic packaging, long distance product transport, and particularly fish feed made from wild-harvested fish.

Avoidable loss

(waste)

Currently, excess nutrients from fish waste are not being utilised effectively. There is a possibility the government will start charging for this disposal. Both solid and liquid waste streams should be converted into plant fertiliser, and further into the future, full recirculation of the water could be investigated.

Focus on finding a product stream or recycling method for solid and liquid waste that has not been utilised (e.g. filtrates). Consider traditional agriculture add-on (e.g. fruit trees on the property). Analyse water and greenhouse gas emission efficiencies (e.g. LCA) if possible. Reduce pests using IPM.

Small-scale aquaponics can be recirculating with minimal waste. Look for a use for solid fish waste (e.g. traditional garden or bartering). Make use of municipal recycling, composting and green waste programs or lobby for their introduction. Connect with community gardens for potential waste recycling.

Excellent opportunities to build add-ons to the agroecosystem of the basic aquaponics cycle. Cultivating poultry, pigs, insects, soil gardens, bees, and native bush regeneration (e.g. native plant nursery) can all go hand-in-hand with aquaponics, given enough community support and development. Use IPM.

Marine aquaponics such as the GreenWave 3D restorative farm have an advantage that there are no feed or nutrient inputs, and any animal wastes are incorporated into the sea. Waste should be minimised during product handling and manufacture. Land-based saline aquaponics would be similar to freshwater.

Unavoidable

loss

This may be less at Matorka than in other systems, if most hot water is kept inside and utilised for air temperature control, and water that evaporates is captured in greenhouses by condensation and run-off. Threat of natural disaster (e.g. Hekla explosion) needs to be incorporated into financial model.

Depending on the design, evaporation, heat loss, some percentage of plant or fish death (including possible pest issues), N gas emissions, or calculated incomplete recirculation, may all be unavoidable losses. Climatic and natural disaster impacts should be considered.

Evaporation, heat loss and expected percentages of plant and fish mortality are all system losses which can be minimised to some extent, but not completely eradicated.

As with backyard aquaponics, some losses are unavoidable. In urban areas, crime or vandalism is a potential threat which should be minimised through good community connectivity (or possibly better fencing).

Marine aquaponics such as the GreenWave design could be more susceptible to climatic disturbance and damage. Land-based saline aquaponics would have similar losses as in freshwater, depending on the scale.

http://greenwave.org/about-us/

4.4.1 Fish

The fish used might vary considerably for aquaponics operations in different parts of the

world. For example, the aquaponics fish of choice in America, Europe, Asia and Africa,

according to the analysis of web sources, is undoubtedly tilapia. Tilapia, in several varieties

including red, Nile, black and white, is ideal for aquaponics because it is easy to breed in

captivity, it easily adapts to a vegetable-protein based diet, and it grows quickly, producing

tasty flesh with good nutritional qualities. However, in Australia, for example, due to a

number of devastating introduced plant and animal species (e.g. cane toad, fox, rabbit, carp,

Opuntia spp., Lantana sp.), it is illegal to keep tilapia because of the propensity of the species

for quickly naturalising and becoming invasive in sub-tropical to tropical environments (See

Figure 32).

Accidental or deliberate introduction by fish farmers is thought to be the way that Tilapia

spread throughout Asia, where it is now so common that its wide availability is reducing the

commercial viability of farmed tilapia (Athauda, 2010). Sri Lankan authorities are

considering the impacts of introduced tilapia, which can out-compete native fish due to their

Figure 32. Sign installed by a regional Natural Resource Management organisation informing about the impact of tilapia in Queensland, Australia (Supplied: Matt Moore, Catchment Solutions). The fine for possessing a tilapia (dead or alive) is AU$20 000 (Watson, 2016).

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high tolerances for poor water quality, varied salinity, and diverse diet, and have come up

with the idea of developing an all-male hybrid which could be introduced to skew the

population in water bodies (Athauda, 2010). Measures like this may be required in other

invasive populations (such as in other parts of Asia, the USA and Australia), since the

promise of tilapia for food security (Somerville, et al., 2014; Wang & Lu, 2015) is damaged

by negative environmental impacts.

One important consideration for fish choice is the marketability or palatability of a particular

fish in a particular culture. For example, catfish or carp-like fish might be suitable in Asia

but probably not in Australia or Europe, where they are not currently eaten. For innovative

producers and marketers in some places, an unknown but easily grown fish could be seen as

an opportunity, as the marketing of ‘Nordic Tilapia’ in Europe by Matorka demonstrates

(see Matorka website, www.matorka.is for example of successful marketing). In the Pacific,

aquaponics has the potential to improve food sovereignty by allowing local production of

food on islands, but some local groups have shown a cultural resistance to tilapia because

they do not normally eat freshwater fish (Foskett, 2014). This is being overcome by

education campaigns and community advocacy.

To improve the sustainability of an agroecosystem, it would be sensible to choose to cultivate

a native, local species if possible, since the climate would match the species’ tolerance, and

therefore necessitate less energy to heat or cool the water, and reduce the impact on the local

environment should any escapes occur. Australian aquaponics growers have had success

with the local species Murray cod, jade perch and barramundi (Bakhsh, et al., 2014),

arguably because regulations on tilapia have forced innovation.

Perhaps the biggest concern in improving the sustainability of the aquaponics agroecosystem

is related to the fish feed. As discussed in Section 3.1.7, there is rapid innovation in fish feed

proceeding, with insect and algae protein sources showing particular promise for replacing

unsustainable ingredients in commercial fish feed (Rust et al, 2011):

Another way to improve the sustainability of the agroecosystem is to make it more like a

natural ecosystem by increasing the biodiversity, and increasing the number of trophic levels

involved. The Matorka model of using more than one fish species is one example of how

this could work. Two fish species are farmed, Tilapia and Arctic Char, although because

http://www.matorka.is/

both are currently being fed the same feed, the full potential of the trophic difference is not

yet being realised.

There are many examples of such experiments in IMTA. For example, researchers showed

that cultivating sea bream and grey mullet together in a land-based saline facility which also

grew algae, was effective because the mullet could live off the waste sludge that dropped to

the tank bottom from the sea bream cages (Shpigel, et al., 2016).

Given enough space and planning, crops or algae used to feed herbivorous fish could be

grown in the same system, using the fish waste as fertiliser. Other options would be to

cultivate herbivorous ‘feeder’ fish to reduce the amount of pellet feed required to get the

main product (e.g. a carnivorous fish) to marketable size, or to focus on an omnivorous

species, such as barramundi. In a backyard-type of operation, it is much more likely that the

fish could be raised on a vegetarian diet, since the lowered rate of productivity would be less

of a problem than in a commercial scenario, where it could potentially make the whole

operation unviable.

4.4.2 Plants

One of the other main problems with current industrial aquaculture, apart from the source of

the feed, is the nutrient pollution caused by the release of fish waste into the environment.

This is a huge advantage that aquaponics techniques can provide traditional aquaculture. By

growing plants, that fish waste can be transformed into a product, as the Matorka trial

demonstrates. In the case of marine aquaculture, macro-algae is commonly used along with

filter feeders like oysters to reduce the nutrient load released by cage-raised fish.

Innovative methods involving macro and micro algae, as well as are being developed to

lessen the impact of aquaculture and improve its sustainability.

4.4.3 Nutrient and energy flows

Agroecological principles are varied, depending on the biophysical and socioeconomic

circumstances of the system being studied. Some design principles are said to be the basis

of the concept, however, and are listed in Table 15 (Altieri et al, 2012).

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Table 15. Agroecological principles for the design of biodiverse, energy efficient, resource-conserving and resilient farming system. (From Altieri et al, 2012).

Enhance the recycling of biomass, with a view to optimising organic matter decomposition and nutrient cycling over time.

Strengthen the "immune system" of agricultural systems through enhancement of functional biodiversity -- natural enemies, antagonists, etc.

Provide the most favourable soil conditions for plant growth, particularly by managing organic matter and by enhancing soil biological activity.

Minimize losses of energy, water, nutrients and genetic resources by enhancing conservation and regeneration of soil and water resources and agrobiodiversity.

Diversify species and genetic resources in the agroecosystem over time and space at the field and landscape level

Enhance beneficial biological interactions and synergies among the components of agrobiodiversity, thereby promoting key ecological processes and services

These important concepts should underpin any new aquaponics system as well.

4.4.4 External elements

For aquaponics to have a positive impact on the environment, and therefore be a useful tool

for ecosystem-based management in coastal areas, it is the external elements of the

agroecosystem that need to be carefully managed. In Figure 1, there are red and green arrows

indicating inputs and outputs from the farm. For the most efficient production in the most

sustainable way possible, the green arrows should be maximised while the red arrows are

minimised. Green arrow inputs to maximise are:

• Renewable energy sources. Solar energy for plant growth and renewable energy for

electricity.

• The atmosphere. Oxygen and carbon dioxide as well as fresh water from a river or

rainwater reservoir.

• Recycled materials. For example, food waste products being used as a component of

fish feed, and repurposed building materials.

• Renewable human input (i.e. intellectual capital, human skill and manual labour).

• A consistently high or growing stream of sustainable goods to the market. On a small

scale this could just be a consistent level of food production for a local community.

On the other hand, the process should seek to minimise the red arrows, which are:

• Non-renewable human inputs (i.e. petroleum products for transport, coal-generated

electricity, new infrastructure, and unsustainable fish feeds).

• Losses both unavoidable (such as evaporation of water and radiation of heat energy),

and

• Avoidable (such as bird predation on fish, or release of nutrient-rich water into the

environment).

A detailed analysis of the impact of an aquaponics facility on a coastal community or family

could seek to quantify the inputs and outputs in economic terms, and/or in terms of energy

and nutrient flows, in the same way that a life-cycle assessment can be undertaken.

If it were possible to transform aquaculture systems into agroecological systems, the

destructive impacts of the industry on coastal ecosystems would be alleviated. Mendez et al

(2013) discuss political ecology with the example of how some environmental degradation

can be traced directly to social marginalisation. Similarly, destructive fishing and

aquaculture practices in some places may have social-political roots. As Mendez et al write,

“If farmers cannot access the resources they need, […], they cannot continue to maintain or

develop sustainable agroecosystems.” Therefore, it is essential to consider the human and

societal elements of the agroecological system as of equal importance to the ecological and

agricultural components.

Altieri et al (2012) propose that for an agroecological resilience strategy in a small

community or agricultural region, sovereignty of food, energy and technology are required.

They also suggest that governments therefore have a major role to play in providing

incentives and resources to allow this to happen, but that it cannot be left only to the political

will of governments. Cohesive, participatory social networks, especially in rural (and in this

context, coastal) areas, is once again highlighted as a pathway to change.

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4.5 Improving aquaculture

“Such strategy should be guided by three main principles that should ensure the

contribution of aquaculture to sustainable development: i) aquaculture should

be developed in the context of ecosystem functions and services with no

degradation of these beyond their resilience capacity; ii) aquaculture should

improve human wellbeing and equity for all relevant stakeholders; and iii)

aquaculture should be developed in the context of (and integrated to) other

relevant sectors” (Soto, Manjarrez, & Hishamunda, 2008).

Aquaculture is considered vital to meeting the nutritional needs of the world’s growing

population (Duarte, et al., 2009). However, aquaculture has been practiced intensively, and

in places has had a devastating impact on surrounding ecosystems, fish stocks and native

wildlife located near the aquaculture facility, other fisheries that are under pressure due to

fish meal production, and human health. These problems must be overcome if essential food

production is going to be maintained and sustainability of the industry ensured.

The philosophy of agroecology, and techniques from aquaponics and IMTA can be utilised

to overcome the problems that aquaculture currently has.

Five ways aquaponics can improve aquaculture:

1. Alter perceptions about what aquaculture is. If you start thinking about food

production in terms of its impact on the planet, and you learn that food can be

produced sustainably, will you continue to eat food produced by industrial methods?

Aquaponics is also a brilliant tool for teaching the next generation all about where

their food comes from.

2. Allow aquaculture to move - onto land and into areas where people live. That way

we can reduce transport costs, eat more locally, reduce pressure on wild ecosystems

and decrease industrial control of aquaculture.

3. Add to food products available. Currently, “aquaculture” is synonymous with “fish

production”, but many more products than finfish could be grown in all three of

aquaculture’s water types (fresh, brackish and marine). Think seaweed salad, fresh

oysters, crayfish parties and all the herbs and vegetables you can eat. Aquaculture

companies can diversify and increase their green credentials.

4. Produce products to replace wild fish meal. The biggest problem with aquaculture is

its reliance on wild fish harvesting for fish feed production. An aquaponics system

that is built like an ecosystem can grow the ingredients that fish (and other farmed

animals) need to eat.

5. Improve aquaculture sustainability by reducing environmental impacts. Excess

nutrients from sea pens cause dead zones, nutrient-rich run-off from freshwater

facilities contaminates rivers, and chemicals like antibiotics and insecticides harm

marine ecosystems. With aquaponics, we don’t have these problems.

The five points above have been transformed into an infographic that aims to simply display

these points to a non-scientific audience. See Figure 33.

Figure 33. Five ways aquaponics can improve aquaculture

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4.6 Sustainable development

Thinking even more expansively, aquaponics can help the world work towards sustainable

development. Three global trends define the planet’s future: Climate change, resource

scarcity, and a growing population with a higher proportion of people living in cities

(Thomaier, et al., 2014; FAO, 2017). The development of agroecology rather than industrial

agriculture is important for confronting these issues, and all the problems that stem from

them.

The United Nations’ 2030 Agenda for Sustainable Development is a remarkable and

optimistic document. There are 17 Sustainable Development Goals and 169 targets which

the world’s nations have declared that they will work towards. The goals build on the

Millennium Development Goals, and are based around the following foundation statements

(United Nations, 2015):

People

We are determined to end poverty and hunger, in all their forms and dimensions, and to ensure

that all human beings can fulfil their potential in dignity and equality and in a healthy

environment.

Planet

We are determined to protect the planet from degradation, including through sustainable

consumption and production, sustainably managing its natural resources and taking urgent

action on climate change, so that it can support the needs of the present and future

generations.

Prosperity

We are determined to ensure that all human beings can enjoy prosperous and fulfilling lives

and that economic, social and technological progress occurs in harmony with nature.

Peace

We are determined to foster peaceful, just and inclusive societies which are free from fear and

violence. There can be no sustainable development without peace and no peace without

sustainable development.

Partnership

We are determined to mobilize the means required to implement this Agenda through a

revitalized Global Partnership for Sustainable Development, based on a spirit of strengthened

global solidarity, focused in particular on the needs of the poorest and most vulnerable and

with the participation of all countries, all stakeholders and all people.

Appendix D lists all the development goals and targets that impact coastal areas and food

systems. Figure 34 shows how aquaponics can contribute to some of these internationally

recognised development issues.

Figure 34. How aquaponics can help with sustainable development.

The pictorial conceptual models in figures 33 and 34 above were developed with the

inspiration of the two infographics in figure 35, by The Christensen Fund (The Christensen

Fund, 2013) and the FAO (FAO, 2017).

The Queensland Wetlands Program has published a guide to pictorial conceptual models

which highlights the importance of diagrams for synthesising and communicating ecosystem

science in natural resource management (Department of Environment and Heritage

Protection, 2012). The guide utilises the expertise developed in several research institutions,

including the University of Maryland’s Integration and Application Network (IAN), where

free online resources for creating conceptual diagrams are available and were accessed to

help create Figures 33 and 34 (Various Authors, 2017).

http://www.fao.org/resources/infographics/infographics-details/en/c/471471/

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Figure 35. Inspirational conceptual models, “Soil to Sky of Agroecology vs Industrial Agriculture”, “The future of food and agriculture. The global trends and challenges that are shaping our future”, and “Seven life learnings from seven years of reading, writing and living.” References within text.

4.7 Strategic planning

“We are determined to mobilize the means required to implement this Agenda

through a revitalized Global Partnership for Sustainable Development, based

on a spirit of strengthened global solidarity, focused in particular on the needs

of the poorest and most vulnerable and with the participation of all countries,

all stakeholders and all people.” (United Nations 2030 Agenda for Sustainable

Development, 2015)

Planning for aquaculture to improve by becoming smaller, more diverse and more equitable

may seem disruptive to the industrial methodology used by the companies making the most

money out of aquaculture. But the idea only seems expensive because those companies are

not currently forced to pay the true cost of their activities. Obviously, this is a point that

could be made regarding hundreds of 21st century processes, from aluminium refinery, to

coal mining, to industrial cattle feed lots. Modern capitalist industry rarely pays the cost of

their external environmental impacts (Cortes, 2015). In aquaculture, this means that the value

of sea-pen farmed salmon goes up when costs are reduced, so if the company does not have

to pay for waste removal (because the sea does it) and if the cheapest feed is made from wild

caught fish, then the salmon farming company makes money regardless of these

environmental impacts.

In fact, they could be making money at the expense of other industries, such as tourism or

other fisheries, that rely on the clean environment the salmon farm is polluting (Tasmanian

Abalone Council, 2014). In the short term, there could even be a positive feedback for

aquaculture, whereby wild fish becomes less available or less desirable because of the

impacts of aquaculture companies, who then reap higher rewards because of their

standardised, consistently available product. Aquaculture companies have little incentive to

change under the current economic model – most of us pay so little attention to where our

food comes from that we implicitly or explicitly support harmful food production practices.

This is a gloomy prospect. So what solutions are available?

Firstly, we can consider the free market (a.k.a. business as usual). Presumably in a capitalist

system, environmental problems could eventually work themselves out, and those who profit

from unsustainable practices hopefully do so in the relatively short term. But waiting for the

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aquaculture companies to pollute themselves out of the market, or use up all the wild fish so

they are forced to develop new fish feeds could take as long as reducing carbon dioxide

emissions by waiting until coal companies have finished mining. We know what is necessary

to protect the environment, and we know the result of waiting could be catastrophic, so we

wait only because we can’t convince these companies (and in some cases, Governments) to

change their priorities.

Instead of doing nothing, we could redirect food production under agroecology principles of

participatory, action-oriented, collaborative research. Food production should adjust to local

environments, look at whole systems, maximise long term and intergenerational benefits,

and focus on “processes that diversify biota, landscapes and social institutions” (Mendez, et

al., 2013; Johnston, et al., 2014). The approach of returning to locally focused farming and

“sustainable intensification” is also recommended to avoid overproduction and food waste

(Canali, et al., 2017) and address hunger and nutritional deficits (Rockstrom, et al., 2016).

Golden (2016)’s recommendation to address the predicted nutrient deficiency risk because

of declining fish catches is to consider human health alongside the biodiversity-income

mitigation strategies that fisheries management usually uses. Aquaculture can contribute to

local diets and economies, especially in low-intensity, high-diversity, carefully designed

(e.g. native, nutrient-rich fish), and multitrophic systems (Golden, 2016).

How would it be possible to change food production in this way? People would need to be

aware of the problems, and push for political change. Awareness and activism is indeed, a

major way that society changes. Activism about food production has some excellent recent

examples, including cooperatives being set up to localise food production, fund research and

disseminate information about new ideas (ORICoop, n.d.); and activism in Tasmania

highlighted the ecological destruction caused by salmon farming in Macquarie Harbour,

resulting in changes to regulations, legal action, increased public awareness and discussion,

and divestment from the company by an ethical Super Fund (Ross, 2017).

To look at top-down methodologies, as discussed in Section 4.6, the 2030 Agenda lists

international sustainable development goals that are a priority for the United Nations.

Because of the obvious difficulty we will have meeting some of the goals (e.g. “eradicate all

hunger”), there is a need to establish frameworks for change along the pathway to the 2030

goals. The UNEP has produced one such framework, which aims to review current

knowledge about what factors influence sustainable lifestyles, and propose the strategies and

policies necessary to facilitate changes to lifestyles (UNEP, 2016).

The report examines the different action ‘hotspots’ for individuals, governments, and the

private sector. The most important ‘lifestyle domain’, both because of its worldwide

ecological footprint, and because of its potential for sustainable change, is ‘food and

agriculture’ (UNEP, 2016). As well as personal drivers that affect individuals’ transitions to

a more sustainable lifestyle (e.g. income level, values and ability), there are some “socio-

technical” drivers that influence consumption and determine attitudes towards change. For

agroecological science to have increased uptake and influence in society (which it must do,

for the world’s future food security), its proponents need to focus on the same drivers of

lifestyle influence:

• Awareness

• Knowledge

• Social norms and peers

• Media

• Market prices

• Technology

• Infrastructure

• Policies and institutional support

The report suggests two strategies for influencing change, that aquaponics advocates could

pursue:

• The REDuse framework, which supports bottom-up change-making techniques to

directly empower individuals and communities to understand and choose sustainable

options. The three components target actions that help people Refuse to negatively

impact the environment, Effuse about the positive impacts they can have, and Diffuse

the new knowledge and behaviours throughout communities (Figure 36; UNEP,

2016). However, a caveat on this strategy is that one of the authors of the report was

also quoted elsewhere agreeing that regarding ‘conscious consumerism’, or making

the small, ethically ‘right’ choices, but still within the capitalist system, “It’s a

gesture. Well-meaning signals that you care about the environment. But the action

itself makes no difference” (Wicker, 2017).

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Figure 36. The REDuse methodology described in the UNEP’s 2016 framework on shaping sustainable lifestyles (their Figure 6, p29).

• The second approach for helping develop sustainable lifestyles focuses on the “top-

down” drivers. It is known as the Attitude-Facilitators-Infrastructure (AFI)

framework. It presumes that as well as being encouraged by their peers, people need

guidance and infrastructure to be provided by governments. By building policy

systems around “pro-sustainability stakeholder attitudes, facilitators or access to

sustainable options, and supporting infrastructure”, the AFI methodology aims to

address macro-factors and make sustainability the default option (UNEP, 2016).

Using this model, aquaponics stakeholders could act as advocates and facilitators of

policy objectives and infrastructure development that can assist communities to

claim aquaponics as an accessible lifestyle choice.

Corporate social responsibility is another way change can be driven. Companies can be

persuaded to act responsibly, either by pressure from customers, or because they want to be

known as sustainable organisations. The head of forests at CDP, (formerly the Carbon

Disclosure Project) said recently: “Companies do consider customers as key stakeholders.

Rather than being reactive to backlashes, companies should be proactive in publicly stating

their goals and targets towards sustainability and transparently communicating their progress

regularly” (Riley, 2017).

The UNEP report (2016) also mentions the problem of “greenwashing” which has a negative

impact on consumer trust. It is easy to label products “eco” or “sustainable” regardless of

origin, and difficult for consumers to understand what various labels and processes mean.

This is one example of where government laws and policies could be implemented to support

genuinely sustainable food production, and limit greenwashing.

The idea that companies bother greenwashing, however, does illustrate that the market for

sustainable products is alive and growing. Organic certification and labelling highlighting

sustainable production methods do lead to higher prices for products. Therefore, companies

that lead the way in ecologically sound practices should, and eventually will, benefit. As

mentioned earlier, in Hawaii Tokunaga et al (2015) emphasised the importance of

understanding the market, because in some places the break-even price for an aquaponics

company’s produce would require that the “sustainability premium” is paid by consumers.

4.7.1 Strategies

For aquaponics to realise its potential, the industry needs to build on its advantages (Section

4.2), work to minimise the weaknesses (Section 4.3) and utilise the pathways to changing

the harmful industrial food complex that are outlined above.

Outlined below is one way this could be achieved. I would like to note two things though:

1. As an external analyst to the aquaponics industry, I acknowledge that I am

simplifying the issues. Insiders might have many reasons why the concept below

would be impractical or distasteful to those who are actually working on aquaponics

and IMTA.

2. This is a top-down, big picture approach, conceived while thinking about the

overwhelmingly large 2030 Sustainable Development goals. How can we feed the

world’s people, without exacerbating climate change, while remedying ecological

damage we have already caused and protecting natural resources (especially wild

places) for future generations? Some people might argue that a better approach is

bottom-up, where each individual makes their own effort to live their best life,

communities form to magnify these efforts, and harmful industries make incremental

steps to improvement (which is obviously partly under way; e.g. Guimaraes, et al.,

2016), but I believe that to kick-start the huge world-wide changes we need by 2030,

there will have to be international guidance and governance.

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International movement towards sustainable aquaculture

Firstly, I think it is necessary to create an international combined aquaponics and IMTA

organisation that encompasses government, civil society, academic and private industry

stakeholders. This could be built by combining regional and national bodies that already

exist (e.g. ICES, Aquaponics Association, or World Fish Centre), by further developing the

FAO’s sustainable aquaculture group, and/or by building a ‘task force’ under the UN

Sustainable Development goals system, which breaks down the goals and targets into

related, manageable chunks.

The aim should be for this organisation to become the sustainable aquaculture peak body,

transforming all unsustainable aquaculture practices to incorporate agroecological

principles.

This association should conduct a robust strategic planning exercise (such as an extended

SWOT analysis) for the combined industries, utilising the input of multiple diverse

stakeholders.

Next, the organisation could use the SWOT results and one of the Multiple Criteria Decision

Support methods (Kajanus, et al., 2012) to develop a strategic management plan for the

aquaponics/IMTA industry. Strategies should define actions, networks and resources for

aquaponics practitioners at each of the levels discussed: family scale, community scale

including urban farming, aquaponics in developing contexts, research and education

facilities, and commercial farms using aquaponics, IMTA and agroecology principles.

Targets and actions under the strategies should be “SMART” (i.e. Specific, Measurable,

Achievable, Relevant, Timely), non-discriminatory, participatory and devised with the

philosophy of Ecosystem-Based Management and the UN 2030 principles (see section 4.6

and Appendix D) as guidance.

Multidisciplinary partnerships are repeatedly suggested to guide global change. Golden

(2016) discusses a high-level interaction between international groups such as health

agencies, ocean management organisations, and other actors in government and civil society

to address nutritional poverty caused by wild fish catch declines. The EAT-Lancet

Commission is conducting a global assessment to assess whether a global transformation to

a healthy sustainable food system is possible (Rockstrom, et al., 2016). The Commission

intends to investigate the connections between human health, diet and planetary health to

attempt to reform the global food system and generate political change. In the same way, the

proposed aquaponics/IMTA organisation could develop high-level aims for systematic

change, and be in a position to contribute to other inter-disciplinary initiatives.

Strategies for industry development and transformation of the aquaculture sector might

include, amongst others, those highlighted in the research discussion above:

• We need to alter perceptions about what aquaculture is. Food production needs to

progress under agroecology principles of participatory, action-oriented, collaborative

research, and under Ecosystem-Based Management principles of international, inter-

generational and inter-sector equity. Management plans, and all management

frameworks or proposals for change need to be consultative, collaborative and

evidence based.

• Food production should adjust to local environments, look at whole systems,

maximise long term and intergenerational benefits, and focus on “processes that

diversify biota, landscapes and social institutions” (Mendez, et al., 2013; Johnston,

et al., 2014).

• Aquaculture needs to move - onto land and into areas where people live. The

approach of returning to locally focused farming and “sustainable intensification” is

recommended to avoid overproduction and food waste (Canali, et al., 2017) and

address hunger and nutritional deficits (Rockstrom, et al., 2016).

• We need to add to the nutritional, local food products that are available, and we need

to produce products to replace wild fish meal. Aquaculture can contribute to local

diets and economies, especially in low-intensity, high-diversity, carefully designed

(e.g. native, nutrient-rich fish), and multitrophic systems (Golden, 2016).

• We need to improve aquaculture by reducing its environmental impacts. Excess

nutrients from sea pens cause dead zones, nutrient-rich run-off from freshwater

facilities contaminates rivers, and chemicals like antibiotics and insecticides harm

marine ecosystems. With aquaponics, we don’t have these problems.

• More awareness and activism is needed, to drive change. Increasing awareness will

make it unacceptable for the current methodology of aquaculture to proceed.

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5 Research Summary

5.1 Main findings

The first research output of this thesis was a technical literature review, which summarised

the commonly constructed aquaponics systems designed for families, communities

(including urban farming), and commercial businesses. In order to build a successful

aquaponics system, it is necessary to understand the main system elements: water chemistry,

fish husbandry, and growing plants using hydroponics techniques. Section 3.1 provided a

review of the published information on these aspects, as well as fish feed, food safety, pests,

energy, and technological aspects.

As well as learning from courses and published literature about aquaponics, a great many

people get their aquaponics information from the internet. There are hundreds of groups,

websites, Facebook pages and active forums where one can read information and ask

questions of other enthusiasts, and where advances (usually based on amateur

experimentation) can be broadcast immediately amongst the community. This is an

interesting part of the industry, so a small survey was conducted online in 2012 to try to learn

more about how the aquaponics community operates. The very small size of the survey

meant that no broad conclusions could be made about the community, or about of the way

information is shared within it, but the responses were used to help build a picture of some

of the ‘positive’ and ‘negatives’ of aquaponics.

Based on the literature review and my foray into the online aquaponics community, in 2012,

I designed an experiment in consultation with the staff at Matorka, an aquaculture company

Mt. Súlur, August 2011 (I. Flett)

operating in southern Iceland. The experiment aimed to trial aquaponics techniques in order

to reduce the nutrient load in the fish farm’s effluent, while developing additional marketable

products. The results of the trial demonstrated that plants and marine microalgae can be

grown with fish farm effluent, and that a simple biofilter built on-site was able to effectively

enhance plant-available nutrients. The aquaponics tradition of utilising repurposed and cheap

local materials was carried on during the trial, and this also demonstrated that the techniques

do not require expensive or complicated equipment.

Based on the experiments and the literature review, some recommendations were made for

Matorka (or similar aquaculture companies) regarding the best way to scale up the

experiments to a commercial level. However, the recommendations were made based on the

science of the trial and technical information from the literature, and no specific economic

or business analysis was carried out for Matorka.

The aquaponics industry’s strengths, weaknesses, opportunities, and threats were reviewed.

The positive aspects of aquaponics are that because of its strong community base, it is a very

accessible past-time for most groups of people. The resource use efficiency and potential for

self-sufficiency that aquaponics promises, has been shown to be achievable by small-scale

farmers around the world. At a commercial level, there are a lot of success stories, although

it is not necessarily easy to make money. Aquaponics has great potential for further

expansion and utilisation by commercial aquaculture companies, or innovative start-ups,

particularly in developing countries and urban areas.

The methods of aquaponics, and multi-trophic aquaculture, are highly suited to conscious

consumers who care about local, equitable food production, the environmental sustainability

of the products they buy, and the health benefits of eating fish and fresh vegetables. These

people may be willing to pay a premium for sustainable, healthy, locally produced food, and

aquaponics can also access the organic market, where food prices are higher. Even if the

products of aquaponics cannot be sold at a higher price than those from conventional

agriculture/aquaculture, there could still be financial advantages to aquaponics. Aquaponics

farms can produce multiple products, reduce waste (the disposal of which sometimes costs

money), and manage risk by growing diverse, multitrophic species.

Negative aspects to aquaponics are related to the technical difficulties that can arise, and the

knowledge that is required to build a successful system. At the backyard and community

143

level, aquaponics can be time consuming and expensive, depending on how it is practiced.

It was also reported in the community survey that some people get very discouraged by

setbacks (it is not known how often this leads to people giving up). Additionally, there are

unscrupulous sales-people involved in aquaponics, who may be out to dupe unwary

consumers, or may just be giving bad advice.

At the commercial level, there could be high initial costs during the setup phase, and high

financial risks (although probably no more than in aquaculture). Additionally, regulation is

a concern in some places, where government management may be overbearing (for example

in Australia, where food safety regulations are burdensome), or inadvertently prevent

innovation (for example in Europe, where the ban on insect protein being used as animal

feed has unfortunately hindered the development of sustainable fish feed until recently). On

the other hand, regulation to prevent unsustainable aquaculture could be required in order

for aquaponics to really take off. If industrial aquaculture companies had to pay the real cost

of their environmental impacts, or were completely banned from carrying out some of the

destructive practices, then aquaponics and IMTA techniques could become a lot more

desired and profitable.

The rest of the discussion in this thesis has looked at four connected parts of the future of

aquaponics, starting with a way to look at aquaponics through the lens of agroecology. If the

different parts of an aquaponics system are viewed as an agroecosystem, then its values,

strengths and directions for growth can also be defined in ecosystem terms. A resilient

ecosystem is multitrophic, diverse, adaptable, and grows sustainably. So too with a

successful agroecosystem. In agroecology, the social networks of the agroecosystem are also

considered, so the human capital that goes into the system (for example the knowledge, skills

and effort of the employees) is valued. Using this approach, we see that aquaponics systems

are already agroecosystems, and that the sustainability lessons from agroecology and

aquaponics can be used by other industries.

Aquaponics has the potential to improve the sustainability of conventional aquaculture, in

economic, social and particularly in ecological terms. It is important that aquaculture

problems are resolved in order for nations to meet international sustainable development

goals, and so investment in aquaponics, and policies that encourage the utilisation of

aquaponics techniques should be a priority. Five ways that aquaponics can improve

aquaculture are presented in an infographic in this section.

Aquaponics and its techniques, as well as those from the related field of IMTA, could be

part of the way that the world moves towards the lofty goals of the UN’s 2030 Agenda for

Sustainable Development. The foundational science behind aquaponics is that it is a resource

efficient way to produce essential protein and nutritious vegetables. It can be practiced at

many different scales, in numerous forms, with minimal expertise (although via the internet,

expertise is easy to access). By expanding aquaponics around the world, steps towards some

of the sustainable development targets can be taken; it is a progressive, innovative, accessible

model for local sustainable food production.

The final section of the thesis looks at how this expansion of aquaponics could take place.

What strategic direction should aquaponics industry leaders propose to enable its sustainable

growth in both developed and developing countries, and how would this actually work?

Some ideas are presented to address this question using ‘top-down’ and ‘bottom-up’

approaches, but it is proposed that an international driving force (possibly in the form of an

inclusive overarching peak body for sustainable food production) is required.

5.2 Potential impacts

This research project presents a thorough look at aquaponics, and discusses a potential future

role for the industry in helping to solve global problems.

The experiments conducted at Matorka produced relatively useful results, and some ideas

that could be taken up by Icelandic aquaculture companies. The trial showed that the novel

method of aquaponics involving a flow-through system, rather than a recirculated system

was plausible, even although nutrient levels detected were very low.

A summary of the project was presented as a poster at the GEORG conference in Reykjavik

in 2012 (See Appendix E), and some of the results were included in the final report of the

Aquaponics NOMA research group, which might allow other groups to benefit from the

trials (Skar, et al., 2015).

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5.3 Limitations and weaknesses

As discussed, the aquaponics trial at Matorka could have been improved if it went for a

longer period of time, and if a higher budget had allowed more sampling and time in the lab

to perfect the FIAlab technique. There were also small differences between treatments that

made interpretation difficult (such as the distance of each box from the grow lamp).

One issue with this research is the length of time it has taken to complete it. In the years

since I conducted the experiments with Matorka, the aquaponics industry has developed and

published more results. The company itself has had management changes, and received

funding to increase the size of their facility (Wright, 2016). While they are still focused on

sustainable aquaculture, and helping to advance research into sustainable fish feed sources

by trialling microalgae cultivation (Rannveig Björnsdóttir, personal communication, April

2017), they are not currently progressing the scaled-up flow-through aquaponics system.

The discussion points in Chapter 4, about how aquaponics could theoretically help solve

some global sustainability issues, while relevant and interesting (hopefully), don’t really

have a purpose in this thesis. It would have been nice to be involved with the aquaponics or

sustainable aquaculture community somehow, in order to target research to real-world issues

and produce a report or document intended for a particular audience.

5.4 Further research

Further aquaponics research at Matorka would probably require the development of a

complex and unique aquaponics system, in which nutrient levels are concentrated by

repeated recirculation around a hydroponics system with a biofilter. The method of

introducing new batches of effluent would have to be carefully designed.

More refined nutrient measurements using the FIAlab system would be worthwhile. I think

what we did was ‘on the right track’, there just wasn’t enough time to experiment further

and iron out all the little problems.

Pursuing the marine microalgae as an ingredient in the fish feed is a great idea for Matorka,

since the source of fish feed is still one of the big barriers to sustainable aquaculture, and a

way that aquaponics can be used to improve it.

In general, more publicity and advocacy for aquaponics, and specifically, the way

aquaponics and IMTA techniques can improve the sustainability of aquaculture, would be

worthwhile. A move towards agroecology and ecosystem-focused food production will have

to be made if the world is to meet its sustainable development targets, and more research

about the role aquaponics could have (at different scales and in different places) would be

beneficial.

147

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7 Appendices

Appendix A – Survey details

Text of survey request posted on aquaponics forums:

Hi everyone,

I am conducting research for my Master's in Coastal and Marine Management at the

University of Akureyri (University Centre of the Westfjords:

http://hsvest.is/the_university_centre_of_the_west_fjords/about_the_university_centre/),

Iceland. My thesis is about the state of the aquaponics industry and its potential for

improving the sustainability of aquaculture and the management of coastal resources. I have

created a survey (10 questions) designed to find out how people participate in the aquaponics

community, and to gather some opinions about where aquaponics is heading. This is not a

commercial request or any sort of advertisement.

I would love to have lots of responses, so if you have time, please follow this link, and feel

free to pass it on to your other networks: http://www.surveymonkey.com/s/K3SVVTG

Thanks,

Iona Flett

CMM Master's Candidate

Text of message put on Facebook Interest Group Pages to tell interested participants about

the survey:

Hello. Here is a short, non-commercial survey about aquaponics for my Master’s research.

If you have time, please fill it in and pass the link on to others who might be interested.

Contact me for more information. Thanks. http://www.surveymonkey.com/s/K3SVVTG

http://www.surveymonkey.com/s/K3SVVTG

http://www.surveymonkey.com/s/K3SVVTG

10:40 average time to complete survey

Q1. What is your level of participation in the online aquaponics community? (Please choose all the answers

you agree with)Percentage Number

I am new to the community 14.89% 7

I have been participating in the community for a few weeks 2.13% 1

I have been participating in the community for a few months 27.66% 13

I have been around for years 42.55% 20

I visit forums, read online information and watch videos 68.09% 32

I ask questions on forums and get advice from others 42.55% 20

I answer others' questions and participate in discussions 53.19% 25

I blog and/or make videos about my aquaponics experiences 19.15% 9

I run a forum and/or people seek me out for advice 17.02% 8

Total Respondents: 47

Comments:

Moderator for Aquaponic Gardening Community

Olomana Gardens with Glenn Martinez

I provide aquaponic paid interships for 1-4 weeks.

I have commercail aquaponic system I am very open in showing people freely.

I administer UVI Aquaponics on Facebook

Q2. How often do you participate in the online aquaponics community? This could be reading, answering

questions or discussing aquaponics online. And which websites and forums do you read or engage with?Percentage Number

Very rarely 8.51% 4

About once per week or just on weekends 21.28% 10

Just about every day 51.06% 24

I'm always online and thinking about aquaponics 23.40% 11

I use other resources more than online resources 14.89% 7

Aquaponics is my profession 29.79% 14


I don't have any favorites, just punch in aquaponics and start watching video's and reading forums.

Many, finding new all the time. All the 'commercial' Aussie, US, Hawaii sites for now.

Practical Aquaponics Backyardaquaponics Gumtree classifieds Ebay Google images

Aquaponic Source, Aquaponic gardening community, Backyard Aquaponics

All the forums, Reddit, technical documents: SRACaquaculturehub.org aquaponicsinparadise.com murrayhallam aquaponicsassociation morningstar

thegrowingpower

backyardaquaponics.com/forum backyardaquaponics.com ibcofaquaponics.com

BYAP Forums DIY Aquaponics YouTube

http://www.backyardaquaponics.com/ http://www.baqua.org.uk/ http://www.growfish.com/aquaponics.html

http://backyardaquaponics.com/forum/ http://www.aquaponics.net.au/forum/forum.php

I have many contacts for aquaponics is complex operationUVI Aquaponics Facebook Aquaponics community SnS aquaponics listserve Yahoo tilapia group Ohio State

University Aquaculture List Serve

http://www.backyardaquaponics.comFacebook,YouTube,The Aquaponics Assn.,ATTRA,SARC,The Aquaponic Doctors,Bing,AVG Search, Google and

many others

Q3. Where do you get your aquaponics products? (Select as many as you like) Percentage Number

From a specialised seller of aquaponics products 34.09% 15

From hardware stores or other non-specialist stores 70.45% 31

I try to make my own parts whenever possible 68.18% 30

I am not very handy and buy most parts/products 6.82% 3

I like to use recycled/repurposed parts whenever I can 54.55% 24


Comments

A locqa hydroponics store is my main source for pumps, media, aeration devices, and other shared hardware. I

build all of my own beds and tanks. Hydroponics shops are a great source.. not many know much about

aquaponics, but they have all been very excited about learning more from somebody doing itLive in Coast of Canada so no specialized stores and shipping costs us a fortune so we try to make our own

whenever possibleI have a 20,000 L under floor cistern. In floor heating greenhouse at 42 deg N latitide. Attached under ground to a

24 ft unheated raceway outside. Water depth is 1 foot. I hope to grow vegies in the unheated glass raceway from

April 1, 2013 to say November. I hope the water temp prevents freezing.Anywhere I can get quality parts the cheapest! I use Aquaponic Source to find recommendations for brand

names.Large items are repurposed (tanks and filters). Smaller plumbing items are Home Depot or Ebay. AP supplies

mostly online, no good local resources.

Waimanalo Feed Store Hardware Hawaii The Home Depot Diamond Head SprinklerCraigslist FlexPVC.com for rarer PVC parts handy for aquaponics Lowes/Home Depot/Amazon for general

construction supplies

I'm still in the process of designing and planning a system to go in my garden.

Still planning

I feel it is what you building for there is so many ways too go about this.

Aquatic Eco Systems Hydro Gardens Alladin Lights Dripworks Johnny Seeds

IBC's make great growbeds, still working on building a larger fishtank, right now using a "kiddie pool" 8' dia,

about 650 gallons

I like to reuse and recycle as many items as I can.

Iona and Phil

Typewriter

Appendix B - Survey Responses

Q4. What is your garden like? (Select as many as you like) Percentage Number

Small - balcony or inside house 6.52% 3

Medium - urban garden or roof-top 45.65% 21

Large - big garden or rural property 30.43% 14

Commercial - I can make money out of this thing 19.57% 9

I (plan to) eat the fish regularly 41.30% 19

The fish are only to provide nutrients 21.74% 10

I (plan to) eat the fish occasionally 32.61% 15

I get a steady supply of veggies for myself and my family 54.35% 25

I occasionally eat fresh produce from my garden 15.22% 7

I sell or swap veggies because I have plenty 17.39% 8

Aquaponics is my main business 30.43% 14

I am (trying to be/mostly) self-sufficient 54.35% 25


Comments

8' x 6' inside diameter

Vegetarian production - koi for fish, not harvested.

Greenhouse. Ideally will be able to sell locally regularly....not there yet!

I grow sour & sweet cherries, elderberries, rhubarb, cherry tomatoes, paw paw, straw & raspberries, Jesuit &

Bartlet pears, asparagus. I start all my own geraniums, succulents. My Amarillo bulbs are dividing. My in floor

heater, filter clogged and aquarium heater could not keep up. Tilapia died. Gold fish are ok.

My system is still "warming up". No consistent yields as of yet, but lots of potential.

Small Commmercial

16.5 acres

Building it for a nonprofitI haven't as yet set up a system but do grow fruit and veg in my garden and allotment. I am planning and

researching at the moment.

80m2 garden 6 months dry weather, water storage is an issueFoodchain urban indoor system Kentucky State University research systems University of Virgin Islands

commercial researchmy system is in my basement, using regular t8 flourescent lights (32watt) and about 200 fish, with 4 growbeds,

each growbed is 1/2 of an IBC tote

Reusing a 15' pool with 500 tilapia and raising fry in 55 gal. aquariums .

Q5. What type of community do you live in? And what country (and state or county) do you live in? Percentage Number

Urban 17.95% 7

Suburban 41.03% 16

Rural town 17.95% 7

Rural property 33.33% 13


USA, Dodge City, KS USA Canada

United States 18 3

USA Australia Europe S + C America

Small island of west coast of canada 6 2 2

Australia , South Australia state

Australia - Queensland

Canada

usa

Canada

IL, USA

Indiana, USA

USA, Hawaii

Shore line community - Morro de São Paulo, Bahia - Brazil

Louisiana

norway

australia

usa

United States

Australia

US

USA, South Carolina, Greenville County

England

Australia

USA

Live out in country

USA, Frankfort, KY Kentucky State University

USA

usa

USA

Australia, Queensland

USA

PUEBLA.PUEBLA .MEXICO

Q6. What is your background or profession? Are you working?

Retired, Fedex contractor, water treatment professional,

Health Information Systems, now doing a research degree on citizen science using aquaponics as an example

Web Developer

I am an IT professional. Am currently working in anunrelated field

M.Div. grad

College Student studying Environmental Biology

Retired medical professional, aquarist of long time duration.

Social services

Farmer

IT. yes

Accountant... yes

retired, salesI have a Bachelor of Science and a veterinary degree. I have done surgeries on fish. I have a complete water

chemistry test kit, microscopes with camera.

Student

Army: Retired, Programming: Semi-Retired, Organic truck famering and AP: Start Up

Engineer, Not employed in my field

We have a permaculture and aquaponics farm

Aquaculture Enginner. Actually I am developing an aquaculture project to the community where I live.

Educator/builder

hms instructor on and offshore

construction remodeling and yes I am working.

retail yes

plumer

Computer Programmer / System Administrator Working, Self-Employed

Hospitality

Retired

Was in plastics, technical, now in nursing. Yes.

Integrated Aquaculture Technician

Unemployed. Attempting to make farming and aquaponics my profession.

I have worked in many fields, most recently in fish farming and fire and flood restoration.

Working, Medical/Education

Economic Development. Yes.

My back ground is many I have degree in aguculture management

13 years AP research at UVI 2 years research at Kentucky State I am currently a Master's degree student

Network Engineer, employed full time

Over 30 years in the computer industry. Retired now.

building contractor

Engineering / manufacturing now aquaponics.

Working environmental scientist

Retired Environmental Health Specialist

VETERINARY

Q7. Why are you involved in aquaponics? What are the positive aspects of your experience?

Interesting in a more sustainable way of doing things - especially low water use. Just learningInvolved because i want to know exactly what i am putting in my body. I can grow off season produce in my

greenhouse. Gardening has always been something i wanted to do

Hobby trying to turn into a business

I am seeking self-sufficiency. I like that faster growth rates

To grow organic vegetables, keep the fish as a fun hobby and teach others to do the same; food security and a

living if possible.Stumbled across it about a 1.5 yrs ago and it resonated with me so I convinced my partner that we should try and

see what happens

To learn food production with minimal water requirement .

Fresh vegies and fish that you know what has been applied to them right up to your table. Food safety.

Think it might be future in food production No weeds

grow food

I am ADD and for over 60 years. My green house is attached to my wood working station. We have fresh pies,

new sauces especially elderberry. I get to work inside on crappy days and out side on nice days. I can do my own

thing but have science back it up. I want to make the system work and take it to Guatamala.

Supplements my organic farming. Longer/faster growing season.

Fun, learning, experimenting, growing veggies

Better growing environment, Teaching and education people all we can about this aquaponics.Because is a safe way to produce high quality food. Is the learning and teaching of a self sustainable food

production.Improving agriculture means healthier food for healthier people thus less sickness and imminent reduction of

child obesity!

passion for restoring natural habbitats waterways spawningcreeks etc

I plan to build a commercial system in the near future.

Because it's my job. too many to listI don't have good soil which led me to hydroponics then aquaponics. I love fish and plants and it just seemed

really cool. I love spending time at the garden and feeding the fish.

My hobby

Self sufficiency

I do it and aquaculture commercially for a livingHave been working with a nonprofit organization. They received a grant and with my interest the project fell to

me.Out of interest with a view to building experience and setting up as a not for profit community business. Possibly,

ultimately as a commercial concern.

Looking to end reliance on commercial food supplies

To promote Hawaii's aquaculture industry. Aquaponics uses much less water and plants grow faster

I feel aquaponics is full circule in feeding people and eating very healthy

Research Outdoors in sub tropics Indoors in temperate climates

it's been fun learningI believe it is the future of urban agriculture. Most of our food is imported. People have forgotten how to grow

their own food. If our food supply is interrupted chaos will reign. High school students are beginning to show

more interest in my operations. I believe that aquaponics is the solution to our food, energy, land, and water

crisis.

cutting propagation, learning

To make money.Interested in sustainability. Good feeling of community, worth it to grow locally produced organic food with no

packagingTrying to scale up to commercial production. I am an advocate for the many positive environmental aspects of

aquaponics.

IS LITTLE

Q8. Are there any negative aspects to your aquaponics experiences? (Online or in your garden)Yes, I had a lady donate some fish for my project and I ended up killing most of them. Apparently I used some

water that came off roof (rainwater). But, I had forgotten that I had sprayed insect spray in it to kill the

mosquitoes.

only things I need to learn how to control, eg aphids, lack of iron etcYou get addicted lol. When trying to explain exactly what aquaponics is you always have to mention hydroponics

as a point of reference.. and then people assume your growing marijuana. Convincing them otherwise is almost

impossible.

I truly enjoy every part of it

no

Learning curve.Mistakes are costly when buying parts/pieces. So many different answers on-line, sometimes the advice isn't

always accurate!

Time taken for system to mature

None yet

bugs

space, and I want a larger systemI feel terrible when my fish die. I should have brought them all into the garage but I never thought the $10,000

heating system would fail. I am looking into the German Sunlight heating system for water but I want to retire

before I purchase it.

Yeah, fish die and plants die too. Its just a part of gardening.

Start up is a little costly mostly for the greenhouse. Hard to find complete knowlegde bases. I've had to piece the

info together.

Dealing with outdoor weather extremesYes, when we started building aquaponics, some of the components have lead us ways to make and upgrade

certain components. Do find the best way for a good function in our aquaponics system.

In my region, the lack of matherials and involved people.It is hard work but a rewarding one. Even when you study aquaponic materials and you become the smartass

that thinks that you are the student that is smarter than the teacher then you create new ways of doing things

and you kill all your fish when you make adjustments to improve your system but you disturb it instead and all

your fish turn belly up. Nature also discourages you at times during storms or other type of natural disasters or

drastic weather changes. Perseverance makes a difference between failure and success. Start small and grow big

later!

no

not reallyThe only real negative I have seen is if you do have problems with insects you can't do much about it because you

can't use pesticides, etc. around aquaponics.

Lose of fish due to silly mistakes

heating and part cost

False and misleading information onlineSo many ways to configure the system. Hard to figure out the best way for our setup. Feel like I have to be an

expert in so many areas (fish, plants, hydroponics, plumbing, etc.)

no

Too much information, too many options/variable, hard to know where to start. Expensive initial costs.

I see many people trying too make big money in selling aquaponic systems and never did it.

Many folks giving bad advice that has not been proven. Lack of trained professionals to run systems.

time isn't always available to do as much work as i'd like

It is not as easy as people say. Many people are in it to make money, not to help society. Industry is in it's infancy.

Not much scientific data out there on aquaponics, so there is a lot of hearsay and unsubstantiated opinions.

Nutrient deficiency

It can be difficult to be cost effectiveMaking money on a larger commercial scale is a challenge in the USA so far because of the price of

conventionally produced food.

NO

Q9. Please select all the responses that you agree with, and add any other statements that describe how you

feel about aquaponic gardening:Percentage Number

Aquaponics is a lot of work for not much reward 12.20% 5

I consider aquaponics to be an expensive hobby 14.63% 6

I tried aquaponics but it doesn't really work for me 0.00% 0

Aquaponics works out to be cost effective for me and my family 41.46% 17

I could make money out of running an aquaponics business 51.22% 21

I participate in aquaponics because I like to grow my own food 85.37% 35

I participate in aquaponics because I am passionate about environmental sustainability 70.73% 29

I participate in aquaponics as a hobby 56.10% 23

I would like to see a stronger aquaponics community in my area 73.17% 30

I can apply for grants in my community to help me start up an aquaponics farm or business 21.95% 9

The government in my area should consider providing more funding/assistance for aquaponics 48.78% 20

I think cities should consider aquaponic farming to improve their sustainability or to deal with waste 70.73% 29

Aquaponics has a lot of potential for improving food security in developing countries 75.61% 31

Aquaponics is an important tool for improving the way coastal resources are managed 31.71% 13

I am worried about environmental issues (such as...) and I see aquaponics as a potential solution 65.85% 27

I take part in other environmental activities or sustainability initiatives 60.98% 25

I mostly follow others' instructions for aquaponics 17.07% 7

I experiment a little bit and adapt my design to my space/community 51.22% 21

I am really into design and innovation in aquaponics 60.98% 25


Comments

Climate has a lot to do with adaptation being necessary.Keep the government out of Aquaponics... once you start asking for money they will regulate it. If it/you have a

good product at a good price people will come to you. If you can make a profit or save your life this will get

better on its own without any government assistanceFood in North America is too cheap. When I travel to Central America the local people have a terrible time paying

our prices for food because of the American farm subsides. Food is very expensive for them especially meat. As

the world powers rape the ocean, we are actually starving these people from meat protein.U of Guelph and one

in Britain have stated we throw away 50% of all the food we purchase. If our food was more expensive, I do not

think we would waste so much.

We do whatever it takes to make our aquaponics the best it can be.

Aquaponics is not a magic Crystal Ball that enables you to start making money overnight after you create your

PayPal account and then the next morning you have money. Yes you can grow lots of food while you sleep but

you have to set up a working system. Be aware of predators Aquaponic Experts that sell you expensive systems

for $25,000 to $1,000,000 and they do not guarantee the system to make money. Don't spend that kind of

money. Attend the University of the Virgin Islands Aquaponic Training and/or a hands on training where you have

to work 8-16 hour days for 1-4 weeks to learn how the system works and only then invest in a small system and

do not go beyond until you learn how to produce vegetables without killing your all your fish once per month or

more often. It will happen once or twice or a few more times but you will learn from experience.

The government should not be involved, no need to ask for hand-outs.I have design my own system for I looked at world and talked too Alot of people and experts in doing this for I

experance my design for 5 years in growing everything too see if it all works.

I'm not an "environmentalist"... I'm a businessman.

I am worried about overfishing so aquaponics might help

10. What do you see as the future for aquaponics? Further expansion? Slow decline? More formalisation/

commercialisation? Are there any barriers that you can see to the development of the aquaponics industry?

Any other information you would like to share here would be very welcome!

Personally, if I were younger I would go big time in the commercial part of it. This will be the future for many

people.

I see two completely different branches - an expanding small scale system for personal/family use and a large

scale commercial activity. However I see both of these areas incorporating ideas from other areas and moving

from being traditional aquaponics. I would like to see the results of the survey. I am doing reseach into

aquaponics as part of my research degree as a citizen science project, and would like to mutually share results. If

you are interested, please contact me on [email protected]. Note this is also completely non-commercial, and

research is covered by Macquarie University Australia ethics requirements.

expansion - both individually (decentralized) and commerciallyI definetly see aquaponics becoming highly commercialized. Especially in areas where space is limited and/or soil

fertility is less than desireable

It will continue expanding but will hopefully stay at the local level of production and supply.

I think it will continue to grow and become more popular in backyards and commercially.

Further expansion, local use; ideally every few houses on a street would have a system.Aquaponics will become more popular as gardens get smaller in urban properties . Barriers are component

avaliability (freight costs) and quality feed

Expansion and more commercialisation

hope eventually to expand to commercial and semi retireI want to take my research to Central America/Haiti, Guatemala or Costa Rica. I desire to go to a small village on

the coast and build a small system. We have just built a girls orphanage in Haiti. I would love to go there and

build it. Problem is no one knows about aquaponics, and the political hoops. Other trouble is I am still working.

Dr. S.

My vision for the future of aquaponics is local food produced through small businesses. Barriers: the word

aquaponics is not even in the dictionary! Also, I have a concern that the government will not create a

environment conducive to small business, so that could hinder the aquaponic industry as it grows.

Like too many things, small Mom and Pop operations have been squeezed out by large commercial ops. AP is no

different but I'm going for it anyways. Locally grown high quality food is always in demand.

A source of production in desertified lands

It's the best growing tool for anyone in any country to make grow food

In my point of view, the aquaponic system is the future of the food production.I see more predators ripping people off with providing get Rich Quick Training that grows vegetables in half the

time or 10 times more. Do not take any training from people that tell you how to grow organic vegetables when

they are not USDA certified organic producers themselves or they have never been certified organic. It is possible

to grow 10 times more than the conventional farming but not in half the time. It took years of research and

hands-on to become the 1st. Aquaponic System in Mainland United States to receive and maintain USDA Organic

Certification since April 2009. (Second around the world). Super Natural Organic Farms of America

(www.snofa.net).

to much regulations on small family comunity units

no clue

As one of the original people to push aquaponics into the general populous within the last 10 years, there's been

a lot of change and a lot of movement. Hopefully aquaponics moves in a positive direction rather than being a

flash in the pan, my goal is to ensure that it has a strong foundation so that it can survive and grow well.In the hobbyist/backyard scale I imagine there will be large growth and more small businesses offering home

systems and training. On a commercial scale I feel it would take an extremely large system (like acres) to be

profitable OR to grow something to fill a niche market. If someone can find/invent a grow media that is

extremely lightweight and cheap they would make some money as well. Especially if it can be compressed for

shipping.

It is in it's infancy and more effective means of growth will require reduced energy inputs.Aquaponics as it stands will expand into small market garden farmers until corporate (happening now) step in.

Then the industry will become a little more serious.I see it still in the R&D phase. There are major financial questions that have yet to be answered such as the

profitability compared the that same investment in other farming techniques. I question whether many of the

more publicized farms in the mainland (I believe those on islands have more financial potential) could actually be

profitable if you removed the money they make from training. Sometimes it seems like a pyramid scheme with

them. The money is in the training, not in the farming.

Although there is very little financial support available in this country I feel that aquaponics may well catch on,

but is probably not as cost effective as hydroponics which will always have the larger share of the market.

Increased legislation as to what can be grown, licencing requirements. I can't see it becoming mainstream.

Future expansion. More commercialisation.

I see great future in this field for it can create so many jobs around this field.exponential growth as a hobby/subsistence food system. Commercial systems gaining momentum and will have

success stories around the world

i think it may be close to reaching it's peak as a hobbySlow acceptance, but eventually the only way to be sustainable along with permaculture. Barriers - big

business/agribusiness protecting their own interests, slow acceptance by educational institutions, governmental

ignorance of aquaponics as a valid alternative form of agriculture.

Further expansionWe expect to sell more than $1 million per year, and don't care at all about "aquaponics" as an industry... the

fewer people doing it locally, the better for us.I think there is great potential. So many people are interested when they hear about it, and the more people that

try it, the better it will get.

Further growth and expansion of larger and larger scale farms, as money becomes more available and land,

water and other resources become more scarce. It is more viable in third world countries currently.

Appendix C – Complete experiment results

Part 1 - Experiment Photos

165

167

SUMMARY OF ALL WATER QUALITY RESULTSDate: 25-Sep 1-Oct 11-Oct 22-Oct 29-Oct 3-Nov 11-Nov 19-NovExp. Day: D-27 D-21 D-11 D0 D7 D12 D20 D28 Average n Max Min

Cold Spring Water 0.122 0.201 0.162 2Hot Ground Water 6.906 0.060 0.060 125 Degree tap mix 0.246 0.246 1After charr tanks 1.139 0.279 0.201 0.540 3Outside, before raceway 1.650 0.188 0.919 2Biofilter end 0.205 0.400 0.485 0.820 0.477 4Biofilter end after aeration 0.643 0.643 1Pump tank (unfiltered) 1.289 0.0379 0.339 0.251 0.519 0.362 0.479 0.468 7Matorka effluent to river 0.256 0.210 0.233 2River water upstream 0.181 0.181 1River water downstream 0.195 0.195 1Tap water, pumice TP 0.856 0.101 0.092 0.078 0.424 0.176 0.345 0.167 0.280 8 0.856 0.078 D-27 D0Tap water, hydroton TH 1.065 0.089 0.072 0.073 0.348 0.156 0.197 0.154 0.269 8 1.065 0.072 D-27 D-11Tap water, raft TR 0.090 0.172 0.147 0.156 0.153 0.144 5 0.172 0.090 D7 D0Tap water algae TA 0.078 0.078 1Biofilter, pumice BP 2.801 0.164 0.133 0.433 0.374 0.505 0.576 0.640 0.703 8 2.801 0.133 D-27 D-11Biofilter, hydroton BH 1.330 0.110 0.131 0.442 0.510 0.467 0.579 0.675 0.530 8 1.330 0.110 D-27 D-21Biofilter, raft BR 0.338 0.508 0.391 0.494 0.584 0.463 5 0.584 0.338 D28 D0Biofiltered algae BA 0.057 0.057 1Unfiltered, pumice UP 1.481 0.142 0.197 0.275 0.390 0.416 0.477 0.664 0.505 8 1.481 0.142 D-27 D-21Unfiltered, hydroton UH 0.952 0.100 0.127 0.282 0.447 0.420 0.549 0.698 0.447 8 0.952 0.100 D-27 D-21Unfiltered, raft UR 0.222 0.374 0.703 0.402 0.534 0.447 5 0.703 0.222 D12 D0Unfiltered algae UA 0.061 0.061 1Nutrients, pumice NP 27.644 31.120 2.112 10.894 0.935 14.541 5 31.120 0.935 D7 D28Nutrients, hydroton NH 30.104 28.960 2.218 8.579 0.947 14.162 5 30.104 0.947 D0 D28Nutrients, raft NR 30.210 25.080 2.288 8.671 0.935 13.437 5 30.210 0.935 D0 D28Nutrient algae NA 3.224 3.224 1Cold Spring Water 0.000 0.001 0.001 2Hot Ground Water 0.015 0.002 0.008 225 Degree tap mix 0.000 0.000 1After charr tanks 0.011 0.004 0.002 0.006 3Outside, before raceway 0.039 0.007 0.023 2Biofilter end 0.057 0.042 0.050 0.111 0.065 4Biofilter end after aeration 0.054 0.054 1Pump tank (unfiltered) 0.038 0.002 0.092 0.003 0.044 0.063 0.085 0.047 7Matorka effluent to river 0.017 0.010 0.013 2River water upstream 0.001 0.001 1River water downstream 0.002 0.002 1Tap water, pumice TP 0.011 0.000 0.000 0.000 0.001 0.005 0.000 0.001 0.002 8 0.011 0.000 D-27 D20Tap water, hydroton TH 0.013 0.000 0.001 0.015 0.066 0.006 0.000 0.002 0.013 8 0.066 0.000 D7 D20Tap water, raft TR 0.000 0.000 0.005 0.001 0.001 0.001 5 0.005 0.000 D12 D7Tap water algae TA 0.001 0.001 1Biofilter, pumice BP 0.032 0.031 0.022 0.011 0.032 0.032 0.025 0.054 0.030 8 0.054 0.011 D28 D0Biofilter, hydroton BH 0.033 0.022 0.018 0.039 0.036 0.035 0.031 0.058 0.034 8 0.058 0.018 D28 D-11Biofilter, raft BR 0.038 0.037 0.041 0.051 0.072 0.048 5 0.072 0.037 D28 D7Biofiltered algae BA 0.001 0.001 1Unfiltered, pumice UP 0.031 0.017 0.046 0.011 0.052 0.043 0.061 0.070 0.041 8 0.070 0.011 D28 D0Unfiltered, hydroton UH 0.027 0.021 0.022 0.013 0.048 0.036 0.057 0.047 0.034 8 0.057 0.013 D20 D0Unfiltered, raft UR 0.031 0.060 0.045 0.067 0.078 0.056 5 0.078 0.031 D28 D0Unfiltered algae UA 0.001 0.001 1Nutrients, pumice NP 0.027 0.240 0.111 0.043 -0.001 0.084 5 0.240 -0.001 D7 D28Nutrients, hydroton NH 0.032 0.365 0.137 0.061 0.008 0.121 5 0.365 0.008 D7 D28Nutrients, raft NR 0.033 0.354 0.118 0.044 0.005 0.111 5 0.354 0.005 D7 D28Nutrient algae NA 0.240 0.240 1Cold Spring Water 0.057 0.016 0.036 2Hot Ground Water 0.001 0.093 0.047 225 Degree tap mix 0.001 0.001 1After charr tanks 0.009 0.150 0.127 0.095 3Outside, before raceway 0.140 0.139 0.140 2Biofilter end 0.053 0.130 0.043 0.248 0.119 4Biofilter end after aeration 0.101 0.101 1Pump tank (unfiltered) 0.120 0.657 0.103 0.095 0.545 0.097 0.114 0.247 7Matorka effluent to river 0.128 0.122 0.125 2River water upstream 0.112 0.112 1River water downstream 0.078 0.078 1Tap water, pumice TP -0.045 -0.024 -0.030 0.003 0.023 0.052 0.130 0.108 0.027 8 0.130 -0.045 D20 D-27Tap water, hydroton TH 0.064 -0.030 -0.011 -0.027 0.004 0.067 0.106 0.122 0.037 8 0.122 -0.030 D28 D-21Tap water, raft TR 0.035 -0.025 0.193 0.088 0.088 0.076 5 0.193 -0.025 D12 D7Tap water algae TA 0.097 0.097 1Biofilter, pumice BP 0.024 -0.017 0.004 0.036 -0.021 0.142 0.150 0.129 0.056 8 0.150 -0.021 D20 D7Biofilter, hydroton BH 0.005 0.002 -0.024 0.018 0.036 0.115 0.120 0.127 0.050 8 0.127 -0.024 D28 D-11Biofilter, raft BR -0.004 -0.020 0.113 0.136 0.078 0.060 5 0.136 -0.020 D20 D7Biofiltered algae BA 0.070 0.070 1Unfiltered, pumice UP -0.022 -0.038 0.013 0.036 0.007 0.111 0.136 0.140 0.048 8 0.140 -0.038 D28 D-21Unfiltered, hydroton UH -0.010 0.071 -0.014 0.027 0.042 0.056 0.129 0.082 0.048 8 0.129 -0.014 D20 D-11Unfiltered, raft UR -0.082 -0.012 0.169 0.133 0.122 0.066 5 0.169 -0.082 D12 D0Unfiltered algae UA 0.150 0.150 1Nutrients, pumice NP 13.328 16.432 1.306 6.388 0.733 7.637 5 16.432 0.733 D7 D28Nutrients, hydroton NH 13.371 13.880 1.369 4.180 0.697 6.700 5 13.880 0.697 D7 D28Nutrients, raft NR 13.332 10.152 1.280 4.641 0.711 6.023 5 13.332 0.711 D0 D28Nutrient algae NA 1.123 1.123 1

Day of max

Day of min

NO3

NO2

PO4

Iona and Phil

Typewriter

Iona and Phil

Typewriter

Part 2 - Water quality results

SUMMARY OF ALL WATER QUALITY RESULTSDate: 25-Sep 1-Oct 11-Oct 22-Oct 29-Oct 3-Nov 11-Nov 19-NovExp. Day: D-27 D-21 D-11 D0 D7 D12 D20 D28 Average n Max Min

Day of max

Day of min

Cold Spring Water -0.084 -0.095 -0.090 2Hot Ground Water -0.052 -0.098 -0.075 225 Degree tap mix -0.076 -0.076 1After charr tanks 0.091 0.044 -0.092 0.014 3Outside, before raceway 0.120 -0.091 0.014 2Biofilter end 0.175 0.362 -0.091 -0.086 0.090 4Biofilter end after aeration -0.089 -0.089 1Pump tank 0.268 0.333 0.129 0.085 -0.090 -0.082 0.107 6Matorka effluent to river 0.310 -0.086 0.112 2River water upstream -0.097 -0.097 1River water downstream -0.094 -0.094 1Tap water, pumice TP 0.104 -0.070 0.347 0.006 0.016 -0.004 -0.098 -0.091 0.026 8 0.347 -0.098 D-11 D20Tap water, hydroton TH -0.043 -0.044 0.022 0.042 0.116 0.041 -0.098 -0.089 -0.007 8 0.116 -0.098 D7 D20Tap water, raft TR 0.026 0.020 -0.004 -0.095 -0.090 -0.029 5 0.026 -0.095 D0 D20Tap water algae TA -0.079 -0.079 1Biofilter, pumice BP 0.236 0.210 0.103 0.068 0.056 0.267 -0.096 -0.085 0.095 8 0.267 -0.096 D12 D20Biofilter, hydroton BH 0.255 0.207 0.109 0.108 0.079 0.289 -0.088 -0.089 0.109 8 0.289 -0.089 D12 D28Biofilter, raft BR 0.139 0.095 0.355 -0.094 -0.087 0.082 5 0.355 -0.094 D12 D20Biofiltered algae BA -0.087 -0.087 1Unfiltered, pumice UP 0.257 0.160 0.083 -0.004 0.089 0.285 -0.092 -0.089 0.086 8 0.285 -0.092 D12 D20Unfiltered, hydroton UH 0.253 0.286 0.113 0.088 0.078 0.306 -0.094 -0.088 0.118 8 0.306 -0.094 D12 D20Unfiltered, raft UR 0.213 0.084 0.375 -0.092 -0.085 0.099 5 0.375 -0.092 D12 D20Unfiltered algae UA -0.090 -0.090 1Nutrients, pumice NP 6.119 6.770 0.017 -0.098 -0.085 2.545 5 6.770 -0.098 D7 D20Nutrients, hydroton NH 7.206 6.674 0.073 -0.097 -0.090 2.753 5 7.206 -0.097 D0 D20Nutrients, raft NR 7.494 4.272 0.046 -0.096 -0.088 2.326 5 7.494 -0.096 D0 D20Nutrient algae NA -0.089 -0.089 1Cold Spring Water 7.98 7.49 7.74 2Hot Ground Water 9.91 9.91 125 Degree tap mix 9.50 9.38 9.44 2After charr tanks 8.01 8.27 8.14 2Outside, before raceway 8.89 9.11 9.00 2Biofilter end 8.43 7.62 8.78 7.38 7.58 7.82 7.94 6Biofilter end after aeration 7.92 7.92 1Pump tank (unfiltered) 8.28 8.80 7.70 8.96 7.57 7.82 8.03 8.17 7Matorka effluent to river 8.67 8.67 1River water upstream 7.94 7.94 1Tap water, pumice TP 9.58 9.42 9.65 9.70 9.62 9.59 5 9.70 9.42 D20 D0Tap water, hydroton TH 9.52 9.46 9.66 9.67 9.67 9.67 9.61 6 9.67 9.46 D12 D0Tap water, raft TR 9.57 9.43 9.61 9.73 9.65 9.70 9.62 6 9.73 9.43 D12 D0Tap water algae TA 8.28 8.28 1Biofilter, pumice BP 8.51 7.56 8.53 7.73 7.72 7.88 7.99 6 8.53 7.56 D7 D0Biofilter, hydroton BH 8.48 7.57 8.60 7.72 7.69 7.76 7.97 6 8.60 7.57 D7 D0Biofilter, raft BR 8.59 7.58 8.68 7.75 7.75 8.03 8.06 6 8.68 7.58 D7 D0Biofiltered algae BA 8.30 8.30 1Unfiltered, pumice UP 8.83 7.65 8.85 7.69 7.70 7.89 8.10 6 8.85 7.65 D7 D0Unfiltered, hydroton UH 8.82 7.66 8.81 7.52 7.68 7.79 8.05 6 8.82 7.52 D-11 D12Unfiltered, raft UR 8.84 7.68 8.91 7.72 7.81 7.95 8.15 6 8.91 7.68 D7 D0Unfiltered algae UA 8.30 8.30 1Nutrients, pumice NP 7.81 7.38 8.01 8.66 7.91 7.96 7.96 6 8.66 7.38 D12 D0Nutrients, hydroton NH 7.64 7.37 7.95 8.66 7.90 7.93 7.91 6 8.66 7.37 D12 D0Nutrients, raft NR 7.75 7.38 8.07 8.67 7.91 7.90 7.95 6 8.67 7.38 D12 D0Nutrient algae NA 8.51 8.51 1Cold Spring Water 0.0 0.0 1Hot Ground Water 0.0 0.0 125 Degree tap mix 0.0 0.0 1After charr tanks 0.3 0.0 0.8 0.4 3Outside, before raceway 1.8 0.0 0.9 2Biofilter end 0.0 0.0 1.2 1.6 0.7 4 1.6 0.0Biofilter end after aeration 22.8 22.8 1Pump tank (unfiltered) 4.50 160.8 14 2 214 1.6 2 57.0 7 214.0 1.6Matorka effluent to river 3.2 2.0 2.6 2River water upstream 13.6 13.6 1River water downstream 30.8 30.8 1Tap water, pumice TP 2.8 0.6 1.2 0.0 0.0 0.4 0.8 1.2 0.9 8 2.8 0.0 D-27 D0Tap water, hydroton TH 2.0 0.0 1.6 0.0 1.2 0.0 0.0 3.2 1.0 8 3.2 0.0 D28 D-21Tap water, raft TR 0.0 0.4 0.0 0.0 3.2 0.7 5 3.2 0.0 D28 D0Biofilter, pumice BP 2.2 1.0 1.2 0.0 2.4 0.4 1.6 1.6 1.3 8 2.4 0.0 D7 D0Biofilter, hydroton BH 3.0 0.4 1.2 1.2 2.0 1.2 1.6 2.4 1.6 8 3.0 0.4 D-27 D-21Biofilter, raft BR 0.4 1.6 0.4 2.8 1.3 4 2.8 0.4 D28 D0Unfiltered, pumice UP 1.8 1.4 0.6 10.0 1.6 6.0 3.6 5.6 3.8 8 10.0 0.6 D0 D-11Unfiltered, hydroton UH 3.6 6.8 1.0 3.6 1.2 1.6 4.0 1.2 2.9 8 6.8 1.0 D-21 D-11Unfiltered, raft UR 0.8 2.4 0.0 1.6 4.0 1.8 5 4.0 0.0 D28 D12Nutrients, pumice NP 4.8 3.6 0.0 3.6 2.8 3.0 5 4.8 0.0 D0 D12Nutrients, hydroton NH 3.2 2.0 0.4 16.0 2.0 4.7 5 16.0 0.4 D20 D12Nutrients, raft NR 5.2 3.6 0.4 2.0 1.6 2.6 5 5.2 0.4 D0 D12

pH

TAN

TSS

Plant measurements summary

Experiment Start, 21 OctName No of Leaves Total Leaf Area Average LA Root length

n cm2 cm2 cmAverage Basil 4.0 1.00 0.25 2.51Average Lettuce 2.4 3.08 1.32 2.10Average Rocket 2.0 0.77 0.39 2.44

Experiment End, 19 NovExperiment Box Plant type No of leaves D_NoLeaves TotalLA D_TotalLA Av LA D_Av LA Root LengthBH Basil 5.5 37.5 55.89 5485.8 2.54 915.6 7.43BH Lettuce 8.3 243.8 190.84 6106.0 5.78 337.2 8.81BH Rocket 6.3 212.5 77.30 9921.8 3.09 701.7 9.62BP Basil 6.0 50.0 47.91 4688.6 2.00 698.1 6.75BP Lettuce 8.8 264.6 207.11 6635.2 5.92 347.4 8.30BP Rocket 6.0 200.0 41.43 5270.9 1.73 347.6 7.40BR Basil 5.3 31.3 53.67 5264.2 2.56 921.8 7.50BR Lettuce 8.0 233.3 145.03 4616.2 4.53 242.7 9.72BR Rocket 5.5 175.0 47.20 6019.0 2.15 456.3 12.70NH Basil 5.5 37.5 54.72 5369.1 2.49 894.4 11.18NH Lettuce 7.5 212.5 164.92 5263.2 5.50 315.6 6.98NH Rocket 4.5 125.0 30.86 3901.6 3.43 789.2 10.06NP Basil 5.0 25.0 44.82 4379.7 2.24 795.9 9.63NP Lettuce 7.8 222.9 159.62 5090.6 5.15 289.3 4.66NP Rocket 5.0 150.0 46.97 5989.1 2.35 508.9 7.47NR Basil 5.3 31.3 38.21 3718.6 1.82 627.4 6.51NR Lettuce 7.8 222.9 185.20 5922.6 5.97 351.7 6.27NR Rocket 5.0 150.0 40.42 5140.4 2.69 598.7 11.80TH Basil 4.0 0.0 14.87 1385.9 0.93 271.5 6.84TH Lettuce 4.5 87.5 30.80 901.6 1.71 29.4 7.67TH Rocket 4.8 137.5 8.89 1052.6 0.47 21.3 11.38TP Basil 4.0 0.0 12.26 1125.0 0.77 206.2 7.67TP Lettuce 4.5 87.5 34.22 1012.6 1.90 43.7 4.06TP Rocket 4.0 100.0 4.92 538.4 0.62 59.6 5.27TR Basil 5.0 25.0 23.02 2201.2 1.15 360.2 4.21TR Lettuce 4.5 87.5 36.71 1093.9 2.04 54.2 7.50TR Rocket 4.0 100.0 10.11 1210.8 0.63 63.8 8.92UH Basil 5.5 37.5 50.02 4899.2 2.27 808.9 9.89UH Lettuce 7.5 212.5 114.01 3607.4 3.80 187.3 6.70UH Rocket 5.0 150.0 47.07 6002.2 3.14 713.6 7.98UP Basil 4.0 0.0 28.11 2709.7 1.76 602.4 5.16UP Lettuce 7.0 191.7 150.67 4799.7 5.38 306.8 6.93UP Rocket 5.0 150.0 11.51 1392.2 2.30 496.9 6.36UR Basil 5.8 43.8 42.33 4131.1 1.84 635.8 6.68UR Lettuce 7.8 222.9 146.96 4678.9 4.74 258.4 8.08UR Rocket 4.7 133.3 22.31 2792.1 1.59 313.2 10.69

Mixed for graphing

No. of leaves all plants

Total LA all plants

Av LA all plants

TH TH Combined 75.00 1113.36 107.39TP TP Combined 62.50 892.01 103.19TR TR Combined 70.83 1501.97 159.43UH UH Combined 133.33 4836.24 569.96UP UP Combined 113.89 2967.20 468.71UR UR Combined 133.33 3867.38 402.47BH BH Combined 164.58 7171.20 651.52BP BP Combined 171.53 5531.57 464.36BR BR Combined 146.53 5299.81 540.23NH NH Combined 125.00 4844.61 666.42NP NP Combined 132.64 5153.12 531.37NR NR Combined 134.72 4927.18 525.92

Media Comparison No. of leaves Total LA Av LAHydroton 124.48 4491.35 498.82Pumice 120.14 3635.97 391.91Raft 121.35 3899.09 407.01

Iona and Phil

Typewriter

Part 3 - Plant measurements


Experiment Start, 21 OctName

Average BasilAverage LettuceAverage Rocket

Experiment End, 19 NovExperiment Box Plant typeBH BasilBH LettuceBH RocketBP BasilBP LettuceBP RocketBR BasilBR LettuceBR RocketNH BasilNH LettuceNH RocketNP BasilNP LettuceNP RocketNR BasilNR LettuceNR RocketTH BasilTH LettuceTH RocketTP BasilTP LettuceTP RocketTR BasilTR LettuceTR RocketUH BasilUH LettuceUH RocketUP BasilUP LettuceUP RocketUR BasilUR LettuceUR Rocket

Mixed for graphingTH TH CombinedTP TP CombinedTR TR CombinedUH UH CombinedUP UP CombinedUR UR CombinedBH BH CombinedBP BP CombinedBR BR CombinedNH NH CombinedNP NP CombinedNR NR Combined

Media ComparisonHydrotonPumiceRaft

Stem length Leaf length Total length Fresh Rcm cm cm g

4.33 0.97 8.27 0.0053.05 2.29 7.44 0.0013.48 4.59 10.52 0.001

D_R Length Stem Length D_S Length Leaf Length D_L Length Total Length D_ T Length Fresh R196.7 5.95 37.4 3.45 255.2 16.83 103.5 1.357320.7 3.51 15.0 11.14 387.0 23.46 215.5 0.896294.2 4.79 37.7 7.94 72.9 22.35 112.5 0.780169.4 5.09 17.4 2.82 190.7 14.66 77.2 0.988296.4 2.89 -5.4 11.49 402.5 22.68 205.1 0.983203.3 3.49 0.3 5.36 16.7 16.25 54.5 0.442199.3 5.74 32.5 3.20 230.2 16.44 98.8 1.332363.8 3.36 10.1 10.02 338.4 23.10 210.7 1.289420.4 5.04 44.9 6.85 49.2 24.59 133.9 0.622346.3 3.86 -10.8 3.96 307.8 19.00 129.7 1.190233.1 2.26 -26.1 9.89 332.4 19.12 157.2 0.641312.2 2.35 -32.4 6.34 38.1 18.75 78.3 0.136284.5 4.78 10.3 3.50 261.0 17.91 116.6 0.825122.5 2.73 -10.5 10.38 353.8 17.77 139.0 0.252206.0 3.23 -7.2 4.93 7.3 15.62 48.6 0.136159.8 3.90 -10.0 2.55 162.4 12.95 56.6 1.200199.3 2.86 -6.3 12.61 451.4 21.74 192.4 1.072383.4 5.70 63.7 5.70 24.2 23.19 120.6 0.486172.9 4.01 -7.4 1.73 78.0 12.57 52.0 0.779266.2 2.28 -25.2 4.92 115.0 14.87 100.0 0.297366.3 4.82 38.6 1.87 -59.2 18.07 71.9 0.149206.2 3.46 -20.1 1.73 78.8 12.87 55.6 0.646

93.7 1.65 -45.9 6.03 163.7 11.74 57.9 0.881116.1 3.82 9.9 2.02 -56.0 11.12 5.7 0.042

68.2 3.62 -16.5 1.71 76.7 9.55 15.4 0.454257.9 3.05 -0.1 6.11 167.2 16.66 124.0 0.294265.7 4.62 32.7 1.99 -56.7 15.53 47.7 0.259294.7 4.37 1.0 3.06 215.0 17.32 109.4 1.960220.0 3.34 9.4 8.50 271.9 18.55 149.5 0.982227.0 4.73 35.9 5.80 26.2 18.51 76.0 0.899106.1 3.36 -22.5 1.86 91.8 10.38 25.5 0.792231.0 2.86 -6.4 9.01 293.8 18.80 152.8 1.205160.7 4.63 33.1 5.19 13.0 16.18 53.9 0.077166.6 4.38 1.2 2.43 150.3 13.49 63.1 1.146285.7 3.45 12.8 10.47 357.8 21.99 195.8 1.282338.2 5.74 64.9 4.55 -0.9 20.98 99.5 0.696

Total length all plants

74.63139.73162.387

111.62577.399

119.482143.845112.262147.807121.731101.393123.209

Total Length112.958

82.696113.221







Dry R Fresh S Dry S Fresh Lg g g g

0.000 0.016 0.001 0.0240.000 0.016 0.001 0.0750.000 0.008 0.000 0.014

D_Fr R Dry R D_Dr R Fresh S D_Fr S Dry S D_Dr S Fresh L29650.0 0.044 8983.3 0.273 1605.9 0.016 2462.5 1.809

101695.5 0.030 7689.5 0.317 1936.6 0.014 2328.6 5.268139203.6 0.029 29000.0 0.150 1710.8 0.011 3935.7 1.883

21573.2 0.034 7045.8 0.266 1561.5 0.015 2212.5 1.476111570.5 0.040 10347.4 0.272 1649.4 0.009 1578.6 5.966

78792.9 0.017 16800.0 0.083 894.0 0.005 1757.1 1.02929099.6 0.055 11358.3 0.389 2331.8 0.020 2993.8 1.889

146400.0 0.062 16163.2 0.256 1544.0 0.009 1596.4 4.182110882.1 0.030 29900.0 0.159 1819.3 0.009 3185.7 1.123

25998.7 0.054 11233.3 0.285 1684.7 0.017 2478.1 1.79572729.5 0.019 4847.4 0.256 1542.7 0.012 1971.4 5.05424239.3 0.008 7400.0 0.034 313.3 0.002 685.7 0.78517989.9 0.035 7295.8 0.262 1538.3 0.013 1962.5 1.32028570.5 0.012 3136.8 0.224 1337.0 0.012 2096.4 4.46724132.1 0.013 12400.0 0.057 581.9 0.004 1292.9 1.23126222.4 0.037 7629.2 0.246 1436.9 0.012 1743.8 1.187

121661.4 0.052 13610.5 0.413 2555.5 0.014 2435.7 5.90586739.3 0.029 28600.0 0.098 1077.1 0.006 2114.3 1.03216987.7 0.029 5941.7 0.142 789.9 0.012 1712.5 0.49333695.5 0.016 4163.2 0.173 1012.5 0.014 2382.1 0.81726578.6 0.012 11400.0 0.066 695.2 0.004 1364.3 0.21814055.7 0.031 6400.0 0.113 606.5 0.007 1056.3 0.486

100036.4 0.018 4636.8 0.141 806.8 0.012 2025.0 0.2497310.7 0.002 2200.0 0.034 313.3 0.003 828.6 0.1279851.8 0.022 4525.0 0.154 861.2 0.009 1368.8 0.683

33309.1 0.015 3926.3 0.186 1094.7 0.012 2060.7 0.86946185.7 0.016 16000.0 0.076 809.6 0.007 2400.0 0.23642878.1 0.062 12879.2 0.237 1382.5 0.014 2071.9 1.389

111502.3 0.040 10294.7 0.322 1971.3 0.016 2685.7 3.948160471.4 0.037 37300.0 0.106 1178.3 0.009 2935.7 1.241

17272.8 0.031 6358.3 0.215 1247.9 0.011 1634.4 0.852136831.8 0.038 9873.7 0.159 921.2 0.007 1167.9 3.733

13614.3 0.004 3500.0 0.023 178.3 0.001 364.3 0.30525036.0 0.048 9900.0 0.268 1577.1 0.014 2056.3 1.302

145627.3 0.060 15610.5 0.235 1407.1 0.010 1632.1 5.109124096.4 0.049 48600.0 0.077 832.5 0.005 1578.6 0.590







Dry L Total Fresh Total Dryg g g

0.002 0.045 0.0030.004 0.091 0.0050.001 0.022 0.002

D_Fr L Dry L D_Dr L Total Fresh D_ Tl F Total Dry D_ Tl D7290.1 0.132 6905.3 3.438 7537.3 0.192 6290.06956.0 0.182 4647.4 6.481 7013.8 0.226 4617.6

13725.3 0.103 8620.3 2.813 12415.1 0.143 9085.95930.2 0.083 4288.3 2.730 5964.0 0.132 4286.77890.4 0.211 5389.6 7.221 7825.9 0.260 5337.27455.8 0.055 4603.4 1.553 6810.1 0.078 4874.47618.1 0.093 4862.8 3.610 7917.5 0.168 5503.35501.8 0.145 3665.6 5.727 6186.8 0.216 4416.78146.0 0.060 5010.2 1.904 8369.3 0.099 6278.27231.3 0.096 4985.1 3.270 7163.4 0.167 5450.06669.5 0.189 4832.3 5.951 6431.9 0.220 4498.35663.6 0.045 3755.9 0.956 4150.9 0.055 3438.55292.6 0.071 3666.0 2.407 5246.1 0.120 3883.35883.1 0.177 4509.4 4.943 5325.8 0.202 4117.68939.6 0.069 5739.0 1.424 6232.3 0.085 5367.94750.1 0.064 3283.0 2.633 5749.0 0.113 3650.07809.1 0.205 5243.8 7.390 8011.5 0.272 5579.97477.1 0.052 4323.7 1.616 7088.6 0.087 5483.31915.1 0.044 2251.1 1.415 3042.4 0.085 2726.7

993.9 0.050 1204.7 1.287 1313.0 0.080 1577.81500.6 0.018 1433.9 0.433 1827.9 0.034 2060.31886.5 0.036 1814.9 1.245 2664.8 0.075 2386.7

233.2 0.059 1428.6 1.271 1295.3 0.089 1753.6832.5 0.008 620.3 0.203 802.1 0.013 759.0

2689.2 0.050 2538.3 1.290 2765.8 0.081 2606.71063.3 0.057 1389.6 1.348 1380.1 0.085 1669.91634.2 0.019 1476.3 0.571 2439.6 0.042 2573.15573.6 0.086 4474.5 3.586 7864.5 0.162 5306.75188.5 0.132 3337.5 5.253 5666.0 0.187 3814.29011.6 0.071 5916.9 2.246 9892.4 0.117 7393.63380.0 0.049 2506.4 1.860 4030.4 0.091 2936.74900.0 0.126 3173.4 5.097 5494.8 0.171 3471.12135.7 0.014 1069.5 0.404 1698.9 0.019 1098.75217.4 0.074 3825.5 2.716 5932.7 0.136 4420.06742.4 0.205 5246.4 6.625 7172.7 0.275 5646.94234.8 0.033 2688.1 1.363 5964.5 0.086 5432.1

Total fresh all plants

Total Dry all plants

2061.090 2121.5821587.395 1633.0662195.187 2283.2067807.623 5504.8273741.387 2502.1716356.607 5166.3048988.743 6664.4906866.673 4832.7557491.227 5399.4255915.424 4462.2635601.387 4456.2856949.698 4904.417

Total Fresh Total Dry6193.220 4688.2906884449.210 3356.069275748.180 4438.337982

Appendix D – 2030 Sustainable development goals

relating to food, agriculture, coasts and oceans.

These are the goals and targets from the 2030 Agenda for Sustainable Development (United

Nations, 2015) that relate to food, agriculture, coasts and oceans.

Goal 2. End hunger, achieve food security and improved nutrition and promote sustainable

agriculture

• 2.1 By 2030, end hunger and ensure access by all people, in particular the poor and

people in vulnerable situations, including infants, to safe, nutritious and sufficient

food all year round

• 2.2 By 2030, end all forms of malnutrition, including achieving, by 2025, the

internationally agreed targets on stunting and wasting in children under 5 years of

age, and address the nutritional needs of adolescent girls, pregnant and lactating

women and older persons

• 2.3 By 2030, double the agricultural productivity and incomes of small-scale food

producers, in particular women, indigenous peoples, family farmers, pastoralists and

fishers, including through secure and equal access to land, other productive resources

and inputs, knowledge, financial services, markets and opportunities for value

addition and non-farm employment

• 2.4 By 2030, ensure sustainable food production systems and implement resilient

agricultural practices that increase productivity and production, that help maintain

ecosystems, that strengthen capacity for adaptation to climate change, extreme

weather, drought, flooding and other disasters and that progressively improve land

and soil quality

• 2.5 By 2020, maintain the genetic diversity of seeds, cultivated plants and farmed

and domesticated animals and their related wild species, including through soundly

managed and diversified seed and plant banks at the national, regional and

international levels, and promote access to and fair and equitable sharing of benefits

arising from the utilization of genetic resources and associated traditional

knowledge, as internationally agreed

175

Goal 6. Ensure availability and sustainable management of water and sanitation for all

• 6.3 By 2030, improve water quality by reducing pollution, eliminating dumping and

minimizing release of hazardous chemicals and materials, halving the proportion of

untreated wastewater and substantially increasing recycling and safe reuse globally

• 6.4 By 2030, substantially increase water-use efficiency across all sectors and ensure

sustainable withdrawals and supply of freshwater to address water scarcity and

substantially reduce the number of people suffering from water scarcity

• 6.5 By 2030, implement integrated water resources management at all levels,

including through transboundary cooperation as appropriate

• 6.6 By 2020, protect and restore water-related ecosystems, including mountains,

forests, wetlands, rivers, aquifers and lakes

Goal 8. Promote sustained, inclusive and sustainable economic growth, full and productive

employment and decent work for all

• 8.2 Achieve higher levels of economic productivity through diversification,

technological upgrading and innovation, including through a focus on high-value

added and labour-intensive sectors

• 8.3 Promote development-oriented policies that support productive activities, decent

job creation, entrepreneurship, creativity and innovation, and encourage the

formalization and growth of micro-, small- and medium-sized enterprises, including

through access to financial services

• 8.4 Improve progressively, through 2030, global resource efficiency in consumption

and production and endeavour to decouple economic growth from environmental

degradation, in accordance with the 10-Year Framework of Programmes on

Sustainable Consumption and Production, with developed countries taking the lead

• 8.5 By 2030, achieve full and productive employment and decent work for all women

and men, including for young people and persons with disabilities, and equal pay for

work of equal value

• 8.6 By 2020, substantially reduce the proportion of youth not in employment,

education or training

Goal 9. Build resilient infrastructure, promote inclusive and sustainable industrialization

and foster innovation

• 9.4 By 2030, upgrade infrastructure and retrofit industries to make them sustainable,

with increased resource-use efficiency and greater adoption of clean and

environmentally sound technologies and industrial processes, with all countries

taking action in accordance with their respective capabilities

• 9.5 Enhance scientific research, upgrade the technological capabilities of industrial

sectors in all countries, in particular developing countries, including, by 2030,

encouraging innovation and substantially increasing the number of research and

development workers per 1 million people and public and private research and

development spending

Goal 11. Make cities and human settlements inclusive, safe, resilient and sustainable

• 11.3 By 2030, enhance inclusive and sustainable urbanization and capacity for

participatory, integrated and sustainable human settlement planning and

management in all countries

• 11.6 By 2030, reduce the adverse per capita environmental impact of cities, including

by paying special attention to air quality and municipal and other waste management

• 11.7 By 2030, provide universal access to safe, inclusive and accessible, green and

public spaces, in particular for women and children, older persons and persons with

disabilities

Goal 12. Ensure sustainable consumption and production patterns

• 12.1 Implement the 10-Year Framework of Programmes on Sustainable

Consumption and Production Patterns, all countries taking action, with developed

countries taking the lead, taking into account the development and capabilities of

developing countries

• 12.2 By 2030, achieve the sustainable management and efficient use of natural

resources

• 12.3 By 2030, halve per capita global food waste at the retail and consumer levels

and reduce food losses along production and supply chains, including post-harvest

losses

• 12.4 By 2020, achieve the environmentally sound management of chemicals and all

wastes throughout their life cycle, in accordance with agreed international

177

frameworks, and significantly reduce their release to air, water and soil in order to

minimize their adverse impacts on human health and the environment

• 12.5 By 2030, substantially reduce waste generation through prevention, reduction,

recycling and reuse

• 12.6 Encourage companies, especially large and transnational companies, to adopt

sustainable practices and to integrate sustainability information into their reporting

cycle

• 12.8 By 2030, ensure that people everywhere have the relevant information and

awareness for sustainable development and lifestyles in harmony with nature

Goal 13. Take urgent action to combat climate change and its impacts

• 13.1 Strengthen resilience and adaptive capacity to climate-related hazards and

natural disasters in all countries

• 13.2 Integrate climate change measures into national policies, strategies and planning

• 13.3 Improve education, awareness-raising and human and institutional capacity on

climate change mitigation, adaptation, impact reduction and early warning

Goal 14. Conserve and sustainably use the oceans, seas and marine resources for sustainable

development

• 14.1 By 2025, prevent and significantly reduce marine pollution of all kinds, in

particular from land-based activities, including marine debris and nutrient pollution

• 14.2 By 2020, sustainably manage and protect marine and coastal ecosystems to

avoid significant adverse impacts, including by strengthening their resilience, and

take action for their restoration in order to achieve healthy and productive oceans

• 14.3 Minimize and address the impacts of ocean acidification, including through

enhanced scientific cooperation at all levels

• 14.4 By 2020, effectively regulate harvesting and end overfishing, illegal, unreported

and unregulated fishing and destructive fishing practices and implement science-

based management plans, in order to restore fish stocks in the shortest time feasible,

at least to levels that can produce maximum sustainable yield as determined by their

biological characteristics

• 14.7 By 2030, increase the economic benefits to small island developing States and

least developed countries from the sustainable use of marine resources, including

through sustainable management of fisheries, aquaculture and tourism

Goal 15. Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably

manage forests, combat desertification, and halt and reverse land degradation and halt

biodiversity loss

• 15.1 By 2020, ensure the conservation, restoration and sustainable use of terrestrial

and inland freshwater ecosystems and their services, in particular forests, wetlands,

mountains and drylands, in line with obligations under international agreements

• 15.5 Take urgent and significant action to reduce the degradation of natural habitats,

halt the loss of biodiversity and, by 2020, protect and prevent the extinction of

threatened species

179

Appendix E – Poster for GEORG meeting, 2012

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